I just joined bike forums as I've been shopping the net for a bike as my old Giant Yukon was recently reappropriated without my knowledge. It performed very well for the time I had it, which was at least 8-9 years...
Things were a little easier back when I bought it, as any type of suspension (fork only, if I recall) was on the highest end bicycles.
I've been looking at an '04 Giant Yukon, but also thought that some snazzy full suspension bike might be nice. Now that I've been roaming the forums a bit I see that the hardtails are still very highly regarded.
I was worried about wasting pedal power on suspension movement with a FS bike. I also worried about the strange handling that a FS will exhibit, especialy to a lifetime no suspension rider like myself!
I would use my new bike mostly for urban riding, with some hardpack trails, and a little bit of 'real' mountain bike trail action.
Cook Bros BMX
Giant Yukon (somewhere out there)
This is just my opinion, but I would shop the garage sales, find something 'vintage'; either restore it or modify it. Whatever suits your fancy. Do a couple different bikes. Get excited about it! Old 'lightweight' one to three speed cruisers, muscle bikes, early 10 speeds from Europe and Japan - some really nice bikes are out there...use your imagination. If you want a practical city bike, get some kind of modern commuter or a hybrid and be prepared to spend a little money getting it up to snuff...I personally wouldn't rely on a mountain bike if most of your riding is in town..but city bikes based on 26" wheels are readily available...