I always liked swashbucklers. They allow you to have an extra 1/2 tank or so without subtracting from your thief abilities...with an elf dex of 19, and shadow dragon scale, you're hardly worse off than Keldorn or Minsc, plus you can take over the trapping abilities.
However, I do sometimes miss the ability of the backstab to turn a tough boss + minions battle into an absolute minion rout. Still, I highly recommend it as a class, and it's wonderful as a PC, 'specially if you're evil.
