how many ins/outs do you need?

and stay away from usb, make sure your laptop has firewire so you can use firewire sound...

2 cheap firewire interfaces you can try are:

M-audio 410 - 2 ins 8 outs + 1 midi in/out

Terratec phase 24 - 2 ins 2 or 4 outs (all balanced) 1 midi in/out. You can also use the headphone outs as a second pair of outs giving you 4 channels. They even provide you with a 1/4 splitter cable to split the signal...

I use both and haven't had any problems on a PC. I understand they both have issues with Mac however...