I feel like restarting my Borderlands 2 playthrough.

You should get Krieg !

Salvador is the most boring of all the classes :<

why dont you go to true vault hunter or ultimate vault hunter mode then? also try axton

4 player games = harder enemies if u want things to be harder for u.

Yeah, wait until you get to True Vault Hunter Mode. I had it easy with Zero too (melee build though), and I ended up having more trouble than I expected at the end of the playthrough. Can't imagine how it becomes in Ultimate Vault Hunter mode...

If you want a decent experience, try the Siren or the Psycho. I've had a lot of fun with them, but I'll admit I haven't completed True Vault Hunter with either.

Mechomancer is fun, if you have the DLC. Just let the robot do your dirty work :D

The difficulty curve for normal (especially is single player) is pretty bad. At level 30 you have to be close to the end of the main campaign, I'd suggest you ignore side quests and power through, then up the difficulty for the DLC. Also play with other people.

+1 to finishing main quests and the story (you can come back and do the sidequests later anyway)

At 30, you're close to topped out for the Normal playthrough (max level for quest rewards on Normal difficulty is 35)
If you're actually bored with Zer0 though (rather than it just being a difficulty thing), feel free to create a new character.

Maya (Siren) is my main and is pretty fun and I'm at level 57 with her (at that level, Normal end boss takes me four shots to kill; True Vault Hunter end boss takes me about three to five minutes to kill, but I haven't gotten to it yet on Ultimate and I expect that to be quite difficult). Also, I've yet to really try her elemental skill tree, so there's probably more fun there.

Gaige (Mechromancer) is my other decently-built character and she's at 37. Just starting TVH with her. She's definitely fun at first, but I haven't found a real groove with her yet or experimented much with the available builds.

I have one of each of the other characters too, but they're pretty low level. I want to keep playing Krieg though (if you see a good deal for his DLC, you should pick it up).

Also... when you first hit TVH... you'll probably have an issue with the difficulty again. But this time because it'll be too damn hard! :)

Also, you can always respec Zer0 and go melee the hell out of everything. I haven't played Zer0 much, so I don't know if that improves the experience, but money means almost nothing in this game, so you may as well use it for that if you're getting bored!

if you don't like snipping, try a pistol or melee build.
pistol build is fast passed; the melee builds makes the game horrible easy, with propper equipment and skills, you can kill almost everything with a single blow (exept bosses).
also, for harder modees, you have to complete the main quest (killing the warrior). finish that and jump to the "true vault hunter mode".

Just try playing UVHM OP8 as Krieg. You'll kill yourself with self damage.

Sal is the most OP character in the game, even if it doesn't seem like it.

I did the same thing, beat 1 playthrough with zer0 and wasn't completely satisfied. I played the game with mechromancer next, then TVHM, and am now working on UVHM, along with playthroughs of all but 1 character. The game gets much more fun on TVHM, and difficult on UVHM. It took over 3 deaths each of 4 players to beat boom bewm, compared to 0 on normal and TVHM.

tl;dr play TVHM after beating the game.

TVHM and then UVHM or just start a new character, gone in 60 seconds

Well, if you find Normal mode too easy then just quickly go trough the main quests and move on to True Vault Hunter Mode. It gets significantly less easy when the enemies can shrug off your hits and down you in 2-3 shots. ;)
If you start a new character, chances are you'll still find it easy, so again I'd suggest just going straight to the main quests and trying to get to TVHM quickly. Salvador's ability is actually very powerful. He's the only character who can more or less tank the raid bosses with it without using any other tricks, so don't underestimate him. :P

Gunzerker makes the game even easier, so i don't think it will suit your liking. It's pretty much rush and rage all the time, it's like the game having a fast forward option, that's the definition of Salvador. He will make things look like nothing, but in the hardest mode he might be a requirement to pretty much stand your ground since stuff takes ages to kill untill you find proper gear. This guy is a walking tank of meat that can deal a ton of damage while doing so and run like hell too.

Assassin is fun, you just need to build up to your liking. I started with long range criticals, basically use the ability to see critical spots in enemies that have such spots, try and one shoot them with a sniper, good times. You can also build for meele combat and pistols, the kunai effect looks good imo and it's damn good in team play, each kunai applies a different element on hit, one of which is slag and applies a critical tag that adds more damage to any shots done within like 5 seconds (untill the mark goes off).

Maya, i don't like the siren that much in this game, but she is usefull too, you can play support or medic mostly with her. Her ability is good at times. She's better off played in a group.

Commando, don't know much about this guy myself. I do think this is the aggro support type, probably the most tactical vault hunter available for free along with zero since you can do alot of things with your turret(s).

Krieg, the psycho, imo is the best class in the game, it's fun like hell to play this character. I'll say he is pretty much a little bit off everything, more of a tank'ish meele/close range guy most of the time.

Mechromancer, it's probably an improved version of commando, i used it not that much compared to others but this character makes the game too easy when using her ability too, basically it kills stuff before you even get to it (at lower difficulty settings). I think she plays support only, at least its what i see her being played has online.

Zer0 IS the most boring class in BL2, having a melee centric skill in a game about guns should have given that away

Race through the game without doing side quests or grinding for drops/xp. That's your primary source of easymode in BL/BL2, in my opinion.

UVHM mode is a joke. Normal (not badass) mobs in UVHM have more than million HP, badasses have HP like bosses in TVHM. And the damage increase scaling is irreal, they one or two shoot you anywhere. Prepare yourself if you want to try UVHM, you can die there in every corner. One thing to make your work easier: SLAG.

Easy answer: Don't play a sniper Zero. Switch to melee (Bloodshed) It's much more tense when you are right in the middle of it. You have to be smart about using deception and you have to get more creative with your weapons since having a bladed weapon is a must. It's also a lot more satisfying to melee kill than snipe from a distance.

Just a thought that would save you playing the first 30 levels again. Also play with friends. It's much more fun as a group than solo. If you try to strike out on your own while playing co-op you will die.