I basically play all of them - but I only play between Thanksgiving & Super Sunday. I'll play any of the JK games - however, I only played MotS once (not sure why); for a while, I lost one of my JK CD's and couldn't play that game - I could have gone to eBay but had enough to play w/JK-O & Academy.
First discovered Katarn in DF - which I didn't really play because my PC was old at the time - it was a 286 until 1997. That was the year I downloaded the demo for JK - at the time 20mb was huge (another 5 for DX5). I must have played that demo for about a year. The next year, instead of getting JK, I got another demo for it when I finally bought DF. I knew that DF was older than JK but had no idea just how bad that demo for JK spoiled me for the older game. (my pack of DF came with a 3-level demo for JK, the
1st 3 levels of the newer game.) Finally in '99 I went and bought JK. To this day, I can still appreciate the ways that the Jedi-Quake games haven't quite surpassed JK. I'm also giving MotS a trial run - all my Jedi games played on a 2003 Toshiba Laptop.
I got Outcast in '02. It was great but most of the time I was frustrated by maps that seemed to go on forever without actually progressing the game; also the puzzles were (at the time) impossible. No arguing that lightsabers were much better. To bad Lucasarts can't do a JK-JK2 mod of their own, it's not like that's going to compete too closely with their new JK game (or any other JK game).
Academy - I wasn't bowled over by the demo, and til this day I can;t get over the feeling I'm playing JKO-lite. That said, it's got a lot to recommend it - more vehicles, movie-familiar settings and separate missions.