I have tried different lights over the years. I currently own a stream light stinger, a stream light scorpion, a Surefire 6P, a 6P LED, a 6Z, an E1, E1L, and a L4.
Of them all, I like the L4 the best for any low light stages. LED, compact, pocket clip, holds up to recoil, 120 Lumens, it drops light level rather than just going dead on you.
If I were to get rid of all but one light, I would keep the L4.
Most of my lights were prizes or gifts but I would spend the money to buy a L4
Here is the Sure fire comparison chart
http://www.surefire.com/FlashlightSpecChart
Another thing I consider when making a purchase like this is who supports the matches. Surefire is a sponsor at most if not all major IDPA matches and earns your business with good product, good customer support, and excellent support of the sport.
The L4 is a little over your stated budget so next best would be the 6P LED