Hmmm, have enjoyed the Ranger, Nightshade, Vampiir and Champion when I played a friends. It all depends on your style, what sort of Alb do you play?
Ranger for if you like distance killing and stealthing around, or a melee spec if you want to enjoy the stealth wars (awesome, although clustered servers don't work well for soloers >_<)
Vampiir if you don't mind getting run over by radar groups and killed first in a group since you wear leather and float around with a white face in the Catacombs Client. Totally able to solo in PvE though. Orange con mobs and down are simple. Reds take some skill, and purples are doable depending.
Champions are just insane damage dealers, and with the Banelord ML line with TOA gear and buffs you are probably the main tank for damage, just not protection in Hibernia. Heros are just boring from all accounts, but that's just not my personal style, less options and tools than other classes. Wardens are good if made right, but damage output isn't great normally.
Casters: Enchanter is good solo, have speed pet nukes and point blank spells if needed. Eldritch is good for bolting or bombing depending on spec, no speed no pet though. Mentalist, just not as great in RvR anymore, but light spec is nice with charmed pets, no speed. Animist, good if you plan on camping a static area, no speed, no mobile pet, best spells are pet based. No clue about Bainshees, but I have seen some people cry about them.
Just some thoughts. I have played most classes at 50