Get a used FSR or similar, later 90's are good and probably cheap now. Full suspension literally saves your ass, but the sproing feels wrong until you get used to it. I keep my preload cranked pretty high on road, newer shocks have lockouts if you want to go that route, which is sweet.
I'm a huge fan of Gripshift, mostly because you can trim the front derailleur better than on Shimano, also because it's Ebayable cheap and less moving parts. High end SHimano stuff rocks though, and is very sexy. The rear derailleurs... eh, GripShift is nice there too, but pricey and a little more fragile. For my hardtail beater bike I've had a good workhorse Shimano XT on there forever and it's great.
Vbrakes are fine for much of the riding you'll likely be doing, and are cheap and easy... just like yo momma! Discs rock in Eastern conditions. I used to actually grind through rims in the muck w/rim brakes.
Cranks, whatever you want. Again, XT, I'm running XT on the Stumpjumper hardtail and some RaceFace on the Ellsworth FS. THe more you pay, the less you weigh...
Pedals: I'm still running OLD (like, '95 old) red Ritchey clipless on both bikes, big platform and easy to clip in/out. I'd probably go with some Crank Brothers EggBeaters with the platforms now... and if clipless isn't your thing, the old parallelogram-style Shimano DX pedals (they're not called that anymore but you may remember them if you BMX'd at all in the 80/90's heheh).
Chris King headsets and bottom brackets absolutely RULE if you can justify the buy-in. They are more or less lifetime parts. If not, I've had good luck w/Cane Creek headsets and good old Shimano XT bottom brackets.
chains: Sachs or Shimano. SRAM makes good ones too.
Rims/hubs: again, the more you pay the less you weigh. This is one area I actually do recommend shelling out a little for if you want: rotational mass is felt more here... I've been running Mavic rims (517's.. but they are called somethign else now) with Chris King hubs ($$$$$$$$$$$$$), 14/15ga spokes... But the Stumpjumper is on Sun/XT wheels that are a little heavier but less finicky.
Tires: for street use, there are a lot of good wider options these days. Dirt, I like Specialized tires in general, many options to choose from. My favorite tire of all time though, is the Ritchey Zmax, in 2.35 size. Big tire, but rounded, so you ride on a thin section of it. Very predictable offroad. The Ellsworth currently has a set of Bontrager Jones tires, 2.1f/1.9r, again predictable in UT conditions.
OR you could ebay a couple yr old deal and be pleased as well. Depends on your budget.
