Which of these NPC's is better. Thanks guys

Ferret

In my opinion (4th time through BG2), Anomen is the better of the 2. What I've been doing is completing Jaheira's quests, then trading her in on a new NPC - Valygar, Mazzy, or Cernd. It varies as to who I keep. Anyway, Anomen is a much better fighter, and he can cast enough of the cleric/druid spells that I need. Neither of them have very pleasant personalities though. Anomen is a prig, and Jaheira is bossy.

Try it through with both of them .. you may find you like one better than the other.
Have fun!

This question gets asked sooo many times
It's like asking what's better, a Porsche or a Ferrari. Hmm...that wasn't the best analogy, maybe a Mistubishi Lancer or a Ford Escort.
If you outfit them both with appropriate weapons their fighting skills are very similar.
Jaheira probably has better used as a fighter who can heal while Anomen is more of an offensive cleric with Flamestrike etc.
In my opinion Viconia kicks ass over either of them. Now she's an Audi A4... you have to get the Quattro package to really get the most out of her though...

Have to agree with Memnoch, Viconia's the best. Not only that but she puts out, too!