How are you going to use it? Walking or running? Twenty minute sessions or training for a marathon?
What is your budget?
I picked up this one last summer for around $1700 from Omni Fitness:
Trimline T360
It holds up well to the pounding of my 215 lbs but I rarely run more than 2-3 miles and use it fairly infrequently (treadmills bore me and I'd rather run outside). My wife, on the other hand, uses it 5+ times a week, for an hour at a time. Overall, we're quite satisfied with it.
If you are doing serious training, I've heard good things about
Landice. I have a coworker who runs marathons at a 3 hour pace and he just bought one. Not sure which model, though.