I'm looking for a 3-4 gb mmorpg that has a good community, pvp and a lot of quests
there are quite a few smaller mmorpgs which fit 3-4 gig with pvp...
Champions of Regnum
12 Sky 2
SD Gundam Online
Asherons Call (this is the only pay to play one i think, soon to go F2P)
Be warned - I am a major player of Regnum Online the mmo. I've been playing it for about 2 years and rarely go without logging in at least once a day. You can also look at good alternatives to Regnum such ase Aion online and Aika Online.