Bicycle Mechanics - reface my bike

OK I have a giant atx 870 frame in very good condition. I was going to buy a new bike but i thought to invest in mine. I want to know for around 150 $ what would you recommend to have done to my bike. I will use for light commuting very rarely off road. I live Hbg PA as far as weather. From frame of tire to new gears and breaks.

Can't recommend anything since we don't know what the condition of the bike is.

the bike is excellent condition less then 50 miles in 12 years. just looking to upgrade

Semi slick tires, decent saddle, and grips.

What is Hbg PA?

Oh yeah, no matter where you live a set of good brake pads is a nice idea. Get Kool Stops with salmon compound - the MTB model if it fits.

With only 50 miles on it, we can assume the bike is mechanically "as new". As the guys said, a pair of slick tires will increase your "road" comfort a great deal. Keep your chain lubed and your DRs adjusted and you should be good to go.
Not much sense dropping megabucks on "upgrades" in most cases; money better spent on a different bike.

Hbg is Harrisburg, PA.

I'd get:
- New brake pads (Koolstops)
- New tires (slicks if you predominately do street riding... I like my 26x1.5 tires. You'd also need new tubes)
- Solid fork (again, if you want to do street riding, get rid of shocks. They soak up a lot of energy)
- Lubes (for chain, cables, etc.)

If you want it to do serious road work, then:

1: I'll reiterate slicks. I like the Bontrager Road Warriors (http://store.trekbikes.com/jump.jsp?itemID=1477&itemType=PRODUCT&path=1,2,461,463&iProductID=1477&bShopOnline=1) a lot.
2: Change the fork out for a lightweight rigid one. You've probably got an extra two pounds on that fork.
3: A complex solution: You may find that you can't get in a high enough gear. If that's the case, I'd hunt around for a used road chainwheel/crank in the 48-52 tooth range. That may make it so your front derailleur no longer really works (you'll at least have to move it up the frame), so you might need a new front derailleur. Fortunately, front derailleurs are really cheap (~$10 on Ebay all the time).