I think the X is slightly too big for my liking, plus I had horrendous luck with other Android Motorolas so I just wouldn't take that chance again. The Incredible is on its way out, which isn't necessarily a bad thing. But people with Incredibles love them. I do know the battery life isn't that great but there are tweaks to help improve it. I personally have the Fascinate and adore it. I have had zero problems; not even a battery pull. It's a great size, the screen is vibrant, and while one of my two complaints involved the lack of LED, the ROM I flashed makes the 4 keys @ the bottom light up when I have a notification.
I'd go with the Fascinate, but I'm biased. Pick the one you like the best.