Is your Jeep a toy, or a DD? And, how much time and money are you looking to spend? If your already talking forced induction your definition of cheap isn't the same as mine, and your probably looking for more power than the 2.5 will probably put out.
I am not an expert on the swaps, but from what I understand the easiest would probably be a 4.0 swap. If you know anything about building motors you could do stroke out a 4.0 to 4.5 which gets something like 50 more horses out of it from what I have read, and depending on how much you want to spend you can get all the way up to 5.0L and 300+hp&lbs/ft. The basic stroker could be dome with mostly factory 4.0 and 4.2 parts and can be fairly inexpensive. I would try googling and/or using the search feature to find out about them if your interested.
1987 Wrangler YJ RED 4.2 5-speed, NP231, BFG 31x10.5R15 AT/KO on 15x8 gambler wheels.
Caution!!! Under construction!!!!!! Caution!!!
Finishing a 4.0 Cyl.head swap, Just got an AX-15 NP231J combo to replace the busted t-case and craptacular BA10/5. Adding Nutter bypass. Probably more to come before it is back as a DD!