Nostalrius Begins - Quality wow vanilla realm (1.12)

I've played Wow in most of it's expansions but for vanilla I was a little stumped when it came to picking a class. I want to play something that is effective in both pve and pvp, but also isn't super over populated. I was thinking rogue, but it looks like there are already plenty of them. So what class should I choose?
*Note: I'm fine with healing raids, but being useful in pvp would be cool too.

Honestly; Whatever you desire to do.

There's always guilds looking for people, and if you look in the guild recruitment section then you can get an idea of what people are looking for.

Roll a warlock
Usefull in pve
Funny in pvp
Good solo grind

What Kryp said.

I'd say "roll lock for the free mount, great DPS, and mad PVP trolling skillz" but it really doesn't matter if you can't play one that well. Find something you're realllly good at, and play that.

Warlock is the least played class on alliance side, atleast somewhere on the bottom next too druids.
If you want a fun, good class for both PVE and PVP I would recommend Warlock for sure!
+ "free" lvl 40 mount

I'd go with priest. They aren't as populated as rogue is, get really strong in PvP when shadow specced, have one the most fun spells in the game (mind control, jumping enemies off a cliff/bridge etc), and are always wanted in PvE as well (esp dwarf priest).

Id say druid, only hybrid that can actually function as one in vanilla. Good in pvp and pve but requires some skill to really master. Also one of the least played classes. Also in wpvp you can survive allot with the very handy "run away" skill travel form :p

Warlock is hard pve becuase of debuff slots so limited to x per raid