Personally I love the idea of an assassin but I agree, I was very disapointed with the assassin kit so heres my solution, I use for my main character "Hesperex" an assassin oh course, then I fire up shadowkeeper the BG2 editing tool and increase his 'hide in shadows' and 'move silently' skills by 15 each from the base, and give him a extra star in daggers and lower his taco by 2 from the base. This in game turms nicely makes up for the rather lacking assassin kit and its a perfectly balanced and playable character. Try this if ya like I just thought id throw in my idea. I've also tried increaing his speed to that of a barbarian '2' as apose to '0' but this doesnt realy make to much differance in game other than its nice to be able to scout around quickly wilst under the shadows.

Artemis Entreri is the fictional assassin who inspired me

at www.gis.net/~yos there is a new Assasin kit which i think is better.