Quality:
Hmm, entry-level LBS major brand: Trek, Specialized, etc. Avoid Wally World bikes. Performance Bikes has too much crap from Pacific Cycle or whatever the company that uses Chinese political dissident slave labor to make its bikes.
Purpose:
I bought a mountain bike and transformed it into a commuter/utility bike by replacing the knobbies with street slicks and slapping all sorts of cargo-carying & commuter doo-dads on it. Ron is right, though. The ideal urban/street bike will be a different critter than a mountain bike.
If I wanted to do both WELL, this is what I'd do:
1. Buy entry-level LBS mountain bike like the Specialized Hard Rock (front suspension, hardtail)
2. Buy entire front wheel / tire deal, same size/brand rim as stock. Slap a street slick on it, though.
3. Similar for the rear with the street slick instead of knobby. Also, choose a cassette with a higher HIGH end. If possible, one with the same LOW end. When commuting with my utility/mountain bike, I have never lacked for low-end grunt, but I have lacked high-end legs. There are a buttload of gears with front & rear dérailleurs, and they overlap a lot. Spreading them out would be no biggie.
If you plan on hauling heavy loads with it in urban/utility bike guise, might want them to use tandem bike spokes on the rear rim.
All this is about worthless if you really want a road / racing bike to make your commute as fast as possible.
Be sure to wait for the folks who REALLY know their stuff on this. I am just a duffer.