My favorite bents are the long wheel base, lower bottom bracket designs, like the Easy Racers Tour Easy, the RANS Stratus and Bacchetta Bella ATT. These are very popular as touring bikes. These larger bents are surprising aerodynamic and can be very fast with the right rider/engine.

http://www.easyracers.com/products/t.../toureasy.html
http://www.ransbikes.com/StratusXP10.htm
http://www.bacchettabikes.com/recumb...s/bellaatt.htm

But most people seem to like the SWB designs. Much easier to transport.