[Natty]

I personally don't use an injection cleaners either. For me, only gas goes in the gas tank. I am skeptical of side affects of any cure in a bottle, whether it be a leak stopper, slick 50, injector cleaner, etc. Basically, my last car got majorly screwed when some "Emissions Pass Protector" ate alot of seals and hoses. That was not fun.
I just use 93 octane in hope that it will burn cleaner and leave less deposits. That said, Chevron techron is the only fuel additive/cleaner I would use.
If you just want it to run better, do a full tuneup. Do the labor yourself and you're looking at $150-$200. You'll learn alot and gain experience working on your car.
I am in the middle of mine. I did the fuel filter and all fluids so far. I have to wait for my air filter, plugs, wires, cap, rotor, etc to come in.
Good luck!
Jeff