Im looking for a USB interface with a ASIO sound driver. Any suggestions?

These days any manufacturer who does not support ASIO is banished to the far reaches of the universe.
The easy way to be sure though is to pick the one you want and check their support / driver page to see if ASIO drivers are downloadable.
 

I recommend RME Babyface or Babyface Pro

under 100 dollars ? Focusrite. they are solid with Sonar and cheap, good pre amps.
have midi as well.

+1 on the RME Babyface Pro. I got one to replace my Motu 828x and 6 months of problems just disappeared. My old Cakewalk UA-25 EX works perfectly as well.
Mark.

This belongs in Hardware along with the other 100 similar threads with the same answers.  

Focusrite, I'm with Chuckebaby

bz2838
I recommend RME Babyface or Babyface Pro

BabyFace is a great set up but it cost almost 5X times more than a Focusrite.
but I agree, great units.

I use the Roland Sonar V-Studio 100 and the M-Audio Delta 1010 and all works wel with Sonar X2 Studio.
I look always first to the site of an product how they have suport it with guides and software download and asiodrivers.
My gear will be out of date for some people but it's all I need and works well. 

Without knowing the budget involved or input/output requirements it's difficult to suggest a specific interface.

Other than start by looking at the ranges offered by RME, UAD, MOTU, Focusrite and Tascam.