What about the Masters Spa Brand? They show at our nearby fairgrounds, and seem to have a good BBB rating. A couple of websites seem to rate them highly also.The common belief is that the following brands are all of equal stature but your decision on which one comes down to features and how it feels when you wet test it. Don't buy a tub without trying it first. Can't stress that enough
Hot Springs (made by Watkins)
Caldera (made by Watkins)
There may be a couple I missed but the above are the consistent brands that people consider top of the line. Each generally has a top model line and then has cheaper alternatives.
Do a search for hot tub dealers in your area and start visiting them. Most should allow you to setup a time to try the tub you are considering.
For the record, I own a Marquis Promise. It was a close decision between that tub and one from HotSprings but the size and feel of the promise is what made my decision.