Hey guys I am pretty sure that this is not a thread but I thought that it would be great to list the best mods rating by its being easy to do, cost efficient and effective.
1-Decals (by being conservative you can alter the look of yor truck Inside and out for the price of an FRF sticker $7 or other decals at various prices)
2-Paint Interior Accents (for a measly 50 bucks and uncliping body panels you can change the look of your interior)
3-Simple Sound system components (most ppl have either aftermarket sound system or speakers from a previous car so all you have to do is install the new system using the factory wiring and placement. Just make sure the speakers fit and that you use the kit for the stereo as well)
4-Change of Hvac (it can make a different of look in your truck and there many out there that are white/silver or even changing to LEDs can make it look great.)
5/5.5-Mustang Dome light and Explorer OHC (many are found on this forum for less then $30 (domes), can be painted any colour and for most years use the stock wiring so it just a bolt change. Some later models need extra wiring if you want the map lights, but thats optional. As for the OHC, installation is a little more complex since you have to fab it into your headliner and the wiring is a pain but since your wiring for the dome light might as well do the OHC wiring as well)
6-Headlight mod/Change Tailight or night shade them (as long as you have an oven, and a few tools this will look great on most trucks and thanks to a "how to" its easy for those who want to try it, just make sure you seal it properly. As for the tailights, aftermarket ones are pretty cheap and installation is easy, night shade is cheaper but not always as effective)
7-Seat covers (cheaper then new seats and can alter the look of your interior, but can be a pain to install. Comes in a variety of coulours for 60/40s or bucket seats)
8-torsion bar Crank (****for trucks that do have torsion bars****, if you have the basic how to on car management this should be decently easy for most mister fix its. Its free to my understanding and just requires time and a little knowledge but it may weaken your wheel bearings)
9-New Tires and Rims (easy to do, but can get expensive unless you get rims of a used car that has the right bolt pattern, this will alter your trucks look from stock to either Street machine or Offroad King)
10-Aftermarket Muffler (the muffler itself if using the stock setp up should be pretty cheap if you do it yourself, which most Mr fix its should be able to do but if you want something more custom then jack up the price and the complexity. This is a must have in my opinion whatever engine you have since the Stock Sound of the Ranger is pretty much like manatee with laryngitis.
11-Changing the factory seats or shifter ( I am not talking about the shifter knob itself but the whole arm like hurst kit. I put these together since they can come up to close to the same price and both be equally effective. The seats can change the look and comfort of you truck while the Shifter can change the look and responsiveness of your shifting. Just make sure you find seats that fit in the OEM ranger hardware or you will make this a little more complex)
11-Aftermarket sound system, Subs and Amps (many can do the work themselves but the hardware can be costly and the time can be consuming and there is a little fab work needed if you want tweeters in your doors and the amps and Subs in a nice clean box in the cab. This will sound excellent but be ready to lost what ever cab space the ranger is already lacking)
12-Body lift (cheaper and easier to do then a suspension lift but not as effective can fit up to 31"s without trimming and up to 33s with some trimming
12.5-Lift or lowering (From what I understand Lowering is cheaper the suspension lift unless bagging, these parts can get really expensive and complex to install, but many here have done it themselves. it will change the look and ride of you ranger and either make it more effective with larger rims on the pavement or in the mud with larger tires, but be ready to have a moths nest in you wallet for a while since normally with suspension mods, tires and rims changes arent far behind.
13-From 4x2 to 4x4 conversion (*In you have the proper suspension**** This setup will make you truck more offroad worthy, but you need the whole system from the electrical with the switch to the transfer case and the Diff so parts can be costly and difficulty in changing it is quite high as well)
14-Front End Swap (most rangers have interchangeable parts so a swap is possible and can make your 1998 look like a 2006+. But the cost is high for the most part since you need all the hardware and body panels and J/Y examples are hard to find. Swapping can be simple enough but takes time and a little know how. Make sure you take your time to adjust everything right and once you stop you have to finish the job, no half chairing it
15-Engine Swap (whether you want a honking V8 5.0/4.6L or just want to swap your blown 3L and want to go to 4L SOHC. Engine swaps are very effective will provide more performance and overall Fun To drive increase. This is a lot of work, not for rookies and for those who have the know and the tools then the time is working against you. Few have done and those who do seem really happy with the results).
***More to be added with suggestions from other members