Depends whether you want to see Tito actually winning fights, or just great Tito fights. I can't stand Tito, so I love watching him get beat down. The three you mentioned are all awesome. I especially loved 44. Tito Ortiz VS Randy Couture is a classic in my book. And both Ortiz/Liddell fights are great. His fight with Forrest Griffin at UFC 59 was a terrific bout. Had a good scrap with Vitor Belfort at UFC 51. The first Tito VS Ken Shamrock fight at UFC 40 was actually pretty good. The other Ortiz/Shamrock fights are a joke, so don't bother. Tito was at his dominant best prior to and including UFC 40, and unfortunately a lot of those events aren't out on DVD. His knockout of Evan Tanner at UFC 30 is very impressive. I'd say get the three you mentioned for sure, they're all amazing.
I've been a Tito fan since his first fight in the UFC. If you want to see a great fight regardless of who the winner is check out Tito vs. Frank Shamrock for the middleweight title (now the linear light heavyweight title). You can pick it up on VHS(UFC 22, I think) on ebay or on the UFC Hits volume 2 on DVD. I'd also second the thought about Tito vs. Ken Shamrock 1 and Tito vs. Tanner.