The RME Babyface (Pro or original) is an excellent audio interface.
Rock-solid drivers... can run substantial loads glitch-free at the smallest (48-sample) ASIO buffer size.
Obviously the machine has to be able to keep up with the load...
 
MOTU's AVB series, Ultralite mk4, and new 624 are also very good choices.
MOTU now has so many different models... it can be a bit confusing when comparing.
 
Lynx cards are also excellent low-Latency performers... but they're more niche (those looking for multi-channel digital I/O... or simple stereo analog I/O).
 
If you're near Fort Wayne, Sweetwater's GearFest is June 23rd and 24th.
That's a great time to grab a piece of gear.