I just got the Expilion 600 yesterday. First impression is very positive. Nice, rugged package, incredibly bright, lots of modes to choose from, bike mount works great. I paid $120 at my LBS but I think it is available online for less. There is an Expilion 700 also. The700 is about $140.

Only negative I can think of is that replacement batteries need to be purhased from Cygolite. It is a 18650 Li ion but it is molded into a proprietary holder.