Which Gym Leaders have you struggled with?

Exactly what it says on the tin. It could be anyone in any game, from the original journey through Kanto in Red and Blue to the most recent adventure in Hoenn during Omega Ruby and Alpha Sapphire. I'm interested in knowing which leaders have given you all a greater challenge than usual.

For me, it would have to be Tate and Liza from Emerald. They're already a little tricky since I don't do Double Battles very often but the duo really went overboard for Emerald when they added a Xatu and Claydol into their initial lineup.

I'm not sure how anyone else dealt with this but I found their team in that game to be really difficult. Between drawback free Earthquakes, Light Screen, Calm Mind, Sunny Day and Solar Beam, they locked down my progress for a surprising amount of time before I squirmed through. I then got sweet revenge by crushing them both under my foot in Omega Ruby~

Do you want a list? I blame myself for being underleveled in earlier gens though.

Red/blue/yellow

-Misty with her Starmie
-Lt.Surge with his Raichu (I never used a ground type)
-Maybe Sabrina too. I don't remember well.

Silver and/or HG:

-Bugsy and that freakin Scyther (both)
-Withney and that horrible Miltank (both)
(I managed to defeat her with ease because of rollout Sandslash)
-Morty (my HG nuzlocke)
-Clair (silver)

Ruby:

-Norman and those Vigoroth

Diamond/Platinum (oh boy):

-Every. Single. One of them. (Especially in Diamond)

Black:

-The normal type gym.
I don't remember much of that game.

X:

Pfff.... Too easy with the Exp. All. Maybe it would be better if I didn't use it back then.

Ooh... Especially in Platinum? I've never played it before but I'm hoping to get it soon. If it's possible to get the Hallowed Tower Spiritomb before Fantina then I'll definitely do that. Anyone else I should be prepared for?

Whoops, apparently Diamond and Pearl were harder than Platinum. I mixed the games up. Platinum got nerved.

Few are the leaders that really caused me trouble, actually...

- Whitney: I've never used Rock-types against her, I just prayed that Bayleef would crit her with Razor Leaf.
- Claire: When the moment to battle her arrived, the only thing I had to defend myself was Meganium, but then I included Magneton to my team and problem solved.
- Tate and Liza: Curse you, Sunny Day!
- The first two leaders from BW: Man, I feel that this game really punishes you for not leveling correctly...especially at the beginning TuT

Oh man... Let's not even get started. Now, or the record, when I started playing Pokemon I was three and my family, in general, wasn't well acquainted with the Internet or game walkthroughs. Now, let us begin.

Gen One
- I actually had trouble getting through the Viridian Forest at first. Again, three.
- I picked Squirtle and had a level 40-something Blastoise by the time I hit Erika, but didn't know about getting Ice Beam. I lost a lot.
-Sabrina's warp panels were a pain
-It took me ten years to beat the Elite Four. Ten. Years. And the cart's battery died pretty much immediately after.
-I got Blue on Virtual Console and had zero problems. Never got to beat the E4 though, as my 3DS developed a nasty case of Black Screen of Death (the home menu won't boot) so I need to replace it and then contact Nintendo.

Gen Two
- I picked Totodile. There's a pattern here. Bugsy became a pain.
-I made it a habit to level-grind to level 30 and get a Feraligatr before fighting Whitney.
-I restarted the game a lot because my dad and I could never figure out how to get past the tree. Or Ice Cave.
-Morty wasn't hard, I just had to spam Surf. And cry when I got hit by Curse.
- Oh, Chuck. Why does Dynamicpunch hit so often when you use it?
-claire why am i in this cave
- it took me a while to beat this too but my sister got silver at the same time I got red sooooo

GEN THREE

- My dad made me wait a while to play this one. He ordered a Crystal, a Sapphire, and two Emeralds off Ebay as well as two SPs and an Advance. He played through Emerald and caught all three of the mascot legendaries. He claimed Kyogre, my sister got Groudon and never used it, and I got Rayquaza. Initially, I was disappointed because I thought it was Grass type, but... Well, it was a level 70 Rayquaza. The most trouble I had was blacking out once in the Pokemon League.

GEN FOURRRRR
-I picked Piplup. Crasher. Wake. Uuuugggghhhhhh why
-Bryon wasn't bad. Candice, on the other hand...
-I spent actual days going through Candice's gym. Why are there so many snowballs
-Volkner's gym had a cool maze, but was a pain to navigate. Also, Electric types.

GEN FIVE

-I would have had trouble in Striaton, had I not gotten the MASSIVE TIP to go to the Dreamyard. You know, the plot-mandatory trip there before you can fight the gym? That one. Fortunately, I got a Fire-type there.
-Lenora. Lenora why. My Dewott learned revenge literally AS I beat her. That was annoying.
-Elesa, why do you have to Volt Switching Emolga? Why must you torment me
-Drayden beat me three times because, shockingly, neither my Samurott nor Barkimedes (my Stoutland) could touch his Haxorus.
-I lost to N in his castle and didn't know how to get back in from the Pokemon Center. I reset the game and started over.
-Roxie is a pain in my butt. Every time.

GEN SIX

-Viola is annoying- I lost a Wonderlocke to her because two of my Pokemon couldn't fight and she killed my Espurr.
-The Reflection Caverns are not a Gym but I always find myself dreading them.
-Lysandre isn't a gym leader either but he once killed my entire team. That Gyarados is unfun to fight with an Yveltal alone, I must say.
-I may have struggled with Wattson in ORAS. For once, I chose the Fire starter, and didn't have any Ground types because I'm an idiot.

...That's about it. For now.

Because of my habit of overtraining my Pokemon, I didn't have much trouble with many gym leaders. Here's a few that managed to stump me for a while, though: 
- In Crystal, Clair was extremely difficult for me (but not Whitney, for whatever reason). The level jump was just too high for me, and I refused to raise an Ice type specifically for the battle! 
- In Ruby, Sapphire, AND Emerald, I had trouble with Norman. The main problem is that I never used fighting types or rock types, which made it nearly impossible for any of my playthroughs without a Combusken.
- Finally, in Diamond, I remember Fantina frustrating me. Getting her to show up at her gym was enough of a struggle, but once I got to her, I didn't have any Pokemon with Dark or Ghost type moves.

ORAS Elite Four No. 3 -Glacida? Glacidia? something like that

SOOOOOOOOOOOOOOOOOOOOOOOOOO FRUSTRATING

OMG

LIKE

HER FRIGGEN FIRST FROSSLASS DECIMATES MY ENTIRE TEAM IN LIKE TEN MINUTES FLAT

SO FRIGGEN FRUSTRATING I SWEAR TO THE LORD ARCEUS ABOVE

Clair. Just Clair. The level jumps in G/S/C/HG/SS were very poorly thought out.

The only leader that caused me trouble was Brock in Yellow. You know, when Pikachu hates your guts and everything else in existence? Yeah, that's the one.

Bumping this because this amused me.

---OLD Gen 1---

That was like... what? Back when I was a fetus? lol ('4')( >->)

my first game was pokemon red... I didn't know how to read at the time.
I couldnt beat brock (with charmander, and charmander alone >-> lol) till it was lvl 19
I breezed the cave
Misty though... I wasn't able to beat her till the charmeleon reached lvl 38... (still by itself. I think I was 6 by that time, still unable to read correctly.)
After that the rest of the game was nothing... I even learned how to catch once I reached diglet cave.
Got Green and

---OLD Gen 2---

crystal when I was 8(I was able to read now)... green was obviously easy af
The only trouble I had with a cyndaquil was gym 3 whitney... Fudge her so hard.
rest of the game was easy, till mt silver... I raged quit against red. (returned to kick is butt when I was 12)
I never got blue, silver, and gold... :c

---Gen 3---
Ruby, 10, torchic, easy af... dunno why...
sapphire, 11, treecko, lost against the rival once everytime. May be op with blaziken :c (loved Kecleon upon sight, for I had a pet chameleon at the time, well I still do today aswell... :3 also sableye fudged me up... I consider sableye, kecleon's rival even though it's not)
never got emerald :c

---Gen 4---
Diamond. 13, Pips, this game... no problem till cynthia... my god... same on Pearl. I raged quit pokemon for 6 years
never got platinum, never seen Giratina till gen 6 T-T
Didnt beat Cynthia till gen 6...(transfered my old gen 3 team and wiped her... all lvl 80s+) fudge her everything.

---Gen 5---

age 20
bought all versions, 1 and 2 it on ebay, missed the dream stuff... :c
literal cakewalk. transfered my old gen 3 team over and wiped everyone.
I think I chose shivy at first but I got all three by the next game anyway.

---gen 6---

age 20: I played this one legitimately before transfering my old gen 3 team... picked Froakie (Freakie :3 ) game was so easy... but that was probably due to age and wisdom... x-x

I never played any of the remakes on any of the games, except ORAS, which I started about 4 months ago... nostalgia made me beat the game in less than 2 hours except for the Δ episode... My old gen 3 team is now fully transfered and roaring for gen 7 (οωο) but I slightly changed it over the generations so its sadly not my gen 3 team... :l

(shiny Kecleon, Sceptile, (Mega)Shiny Sableye, Togekiss, Shiny Malamar, Shiny Politoed) it sucks competitively but it's my fav pokes so, yea... ^-^ fun

I'd have to say Garret... He's tough as can be... I mean he forces every one to do at least 100 reps a week just to be allowed to work out the next week and it's really annoying... wait... you're talking about Pokemon right? I haven't really had much trouble with Gym leaders... not because I'm great.. but because I over level my Pokemon a crazy amount before trying a gym.