The type of interface you will need depends on the type of recordings you will be doing.
If you are tracking a live band you will need many more inputs than if you are mainly working alone.
If your input needs are limited, something along the lines of this …
… would probably get the job done nicely.
Or, for a Steinberg product I think the new UR22 looks pretty nice …
http://www.steinberg.net/en/products/audio_interfaces/ur_series/ur22.html
I wouldn’t go lower in price/quality than the examples I’ve given (there are a few others in that price range as well that are nice units). You want to make sure you are getting something with decent mic preamps.