What else do i need to do?

Heres my list over the last year of things I've done....what else should I do?
Replaced
- spark plugs (AC Delco platinums)
- PCV Valve
- top radiator hose
- radiator cap
- 195 degree failsafe thermostat
- mirrors
- head lights
- floor mats
- bug deflector
- air control knob
- cab lights
- wipers
- in-dash lightbulbs
- brake rotors
- ceramic brake pads
- air filter (K&N)
- fuel filter
- vacuum lines
- 4X4 vacuum swtich
- oil cooler hose assembly
- caliper bolts
- caliper bushings
- shocks (Monroe)
- distributor cap
- distributor rotor
- CD player (Pioneer Premier)
- tires (GoodYear Wrangler radials)

Fixed
- door panels
- AC compressor
- passenger seat
- windshield wiper sprayer motors
- anti-lock brakes
- 4x4
- cleaned MAF sensor
- cleaned throttle body

What is still left to do
- replace catayltic converter
- replace spark plug wires
- replace O2 sensors
- get vacuum leak checked out

We don't know what year.

Have you changed all the fluids? Transmission filter?

What's it doing that isn't right?

I agree with OBP, we need more information. If all you are trying to do is prevent further problems from happening you may want to look at: upper and lower ball joints, inner and outer tie rod ends, sway bar bushings, control arm bushings, body to frame mount bushings (basically anything rubber).
Depending on year you may need to look at the spider assembly or the lower intake gasket. These are all problems that tend to rear their ugly heads with blazers. Additionally, if you haven't started to change out fluids you may want to consider going all synthetic from oil to brake and trans fluids. Have you done a radiator flush??
Before we can help you we need more info about the truck - mileage, year, engine and drivetrain info, and any problems that are currently occuring including any codes.

Yea...thats one thing I havent don...is flush out the fluids and change the tranny filter. Can I get some info on how to do that stuff?

You still haven't answered the Million Dollar Question - vehicle info and what are you trying to acomplish???
To drain and fill the trans is pretty easy. Drop the pan, pull the filter and replace filter and pan gasket with the new that you picked up at your local parts store. Top off with a few quarts of tranny fluid and you are ready to go.
To flush the tranny you need to take it to a REPUTABLE trans shop and have it flushed - it is usually not a good idea to take it to a jiffy joint for this - and they will usually replace the gasket and filter in the process. This is usually somewhere in the neighborhood of $100-150 for a good flush and filter for the tranny.
Radiator flush and fill is pretty simple, but remember to flush out the heater core, also. Just make sure you don't turn up the pressure on the hose, it should be low pressure.
edit-Most of this info is already on the boards, just use the search feature found at the top right of the screen.

You still haven't answered the Million Dollar Question - vehicle info and what are you trying to acomplish???
To drain and fill the trans is pretty easy. Drop the pan, pull the filter and replace filter and pan gasket with the new that you picked up at your local parts store. Top off with a few quarts of tranny fluid and you are ready to go.
To flush the tranny you need to take it to a REPUTABLE trans shop and have it flushed - it is usually not a good idea to take it to a jiffy joint for this - and they will usually replace the gasket and filter in the process. This is usually somewhere in the neighborhood of $100-150 for a good flush and filter for the tranny.
Radiator flush and fill is pretty simple, but remember to flush out the heater core, also. Just make sure you don't turn up the pressure on the hose, it should be low pressure.
edit-Most of this info is already on the boards, just use the search feature found at the top right of the screen.
Its a 96 S-10 blazer LT if i havent replaced tranny filter and fluids since i got it a year ago...i dont kno how longs its been since its been done...so i dont have to flush it? i can just drain it and take the pan off...replace the filter and gasket and refill and im good to go? I prolly wont flush it then...unless i need to? but where do i put teh fluid in at? to i just pour it straight into the pan and then put the pan back in place??????

To fill the tranny back up you fill throught the tranny dipstick tube, just use a funnel that has a long and narow tube on it.
When you pull the pan for the tranny just check the fluid to make sure that there are no metal filings or any debris in it. If you are concerned that it is starting to slip, or if there are other problems, then I would take it to a reputable tranny shop for a flush and filter change and an inspection. However, if there are no problems I would just do a fluid and filter change as noted above as part of my routine maintenance.

http://i73.photobucket.com/albums/i215/magnum3456/DSCF0090.jpg
just testin how to get pics here...