I use this little guy up front and a frog in rear. I got that one because it allows tool-less removal so I don't have unsightly mounting hardware on my bike during the day. It's also an ugly color, but nobody can see it when it's in use.

I've also got a second frog I use up front for dual-blinking action to draw a little more attention to myself, and a who-knows-what-brand 3 led rear that i broke the mounting hardware for, which I attach to my bag (when I can find it).