Early on the PvP servers were a mixed bag. I loved the one on one or even taking on two people trying to gank me. Even better was for them to find out I could kill them both and they would come back for revenge until I killing them repeatedly. Chasing them out of the zone.
Hunting some solo gankers was great fun... as long as their level wasn't too far out of league with yours. I even had a hit list of ass-hats who I hunted whenever possible. Well, until so many players hit the level cap and started grieving low level players at spawn areas (as somebody else pointed out earlier in this thread).
Without a doubt some of the best MMO combat to date. I want to try it again but I'll have to start a new character this time. I jumped in for a welcome back thing and could barely remember how to play the old characters.