I used to race MTB's off road (of course). Now I ride occasionally for fun.
I have the following:
1995 Pro-Flex Animal dual-suspension with a 1997 Manitou ti fork, Magura hydraulic brakes, & lots of expensive Ti components & various other upgrades. It now primarily lives on the wall.
1994 Cannondale R500 triple ring road bike, with MTB running gear & 700c wheels, & various other upgrades. It lives in the basement, on an indoor trainer I no longer use.
1991 Trek 7000 MTB with specialized suspension fork & various upgrades. This is my former race bike. I crashed it really hard in September 1994 & have not raced since. It has 26" wheel road tires, & this is the one I normally ride when I ride a bike.
I also have a couple of folding bikes; one is road oriented with full fenders & the other is a dual suspension MTB style. The MTB folder sometimes serves as alternate transportation if one of the SUV's needs to be dropped off for service.
If what you want is a runabout/excercise/general bike, then think hybrid or city bike.
Bicycles are stupid-cheap now compared to what they were two decades ago, & you get so much more now for your money.
Z, any of the bikes you linked to should do just fine. Just make sure you get the correct size frame.