Hello sir.
As with anything, it depends on your needs.
What do you want/plan on using this light for?
For an all-around, general-purpose light that is plenty bright, I'd most definitely go with the Inova X5.
It is an LED light (actually it has 5 LEDs), is more than bright enough for the average user, and has, IMO, very good battery life; about 20 hours or so per set.
I have one of the "original" X5s, and just ordered a new X5 "Tactical" for my father.
New Tactical:
http://www.tadgear.com/x-treme%20gear/flashlights%20main/inova_x5_led_light.htm
Sorry, couldn't find a pic of the old one.
Anyhow, the Tac is better because it has a push-button on the tail, where the original model had a twist-head to turn on, which doesn't work well if you have only one hand free or need the light in a hurry.
Another brand of lights you should look at are Surefires.
http://www.san.surefire.com/surefire/content/comparechart1.html
http://www.tadgear.com/x-treme%20gear/flashlights%20main/surefire.htm
They are excellent lights, and I am going to purchase one soon to use as a precursor to deadly force, as they are (temporarily) blindingly bright and quite stunning if you get flashed in the eyes with one in low-light. (Dusk/dark)
The downside to Surefires is that they have extremely low run-times; usually no more than an hour and a half with the standard bulb, and only 20 minutes with a high-output bulb!
Again, I'm only going to carry my SF as a defensive tool, so the run time isn't that important to me.
Hope this helps!
Drjones