1- Witness for the Prosecution - this one has Ty Power loosing it on the witness stand, sweaty faced, with eyes huge and mouth contorted.... what a great actor as the smarmy Leonard Vole!!! He was so likable yet vile!
2- The Eddie Duchin Story - made me cry more than once. He was so great in it in every way, "Merry Christmas!" to great piano interpretation, etc.
3- The Long Grey Line - his brogue was so consistent, and great! Forgot it was Tyrone Power at times because he became "Marty"...
4- In Old Chicago - great movie, he was great, Ameche was great, Faye was great, and the mother was great.... superb fire and demolition, Ty gets hurt and is bleeding, completely adorable, wanted to hug him myself! Moving and terrible, great and terrible, huge cast, all I can say is "wow"!
5- Alexander's Ragtime Band - He did such a great job, and was so entertaining, handsome, and on cue for every instance! I thought the entire acting team was superb in this! Also, scenes of the SF Cliff House, Fairmont Hotel, etc, were wonderful, grand etc. The music was great, the walk through history was great, and the entire show was so well done!

Honorable Mention:
The Mask of Zorro (never get tired of this)
The Luck of the Irish (watched this so many times, and still, very cute)
Nightmare Alley (so creepy and intriguing that you can't look away.... BTW Great Title!
That Wonderful Urge (Gene Tierny is great in this)
The Razor's Edge (Should have won an award for HIS acting, and Gene Tierny was wonderful)
Son of Fury (he is beautiful in his swimsuit, and Tierny is also, plus the great fight scenes with fists - w/George Sanders)
Sun Also Rises (his voice in this was great, and he played so low key, angry, apathetic, self indulgent, with a great cast of co-actors)
Blood and Sand (he was so young and SOOO handsome.... I believed that he could fight bulls in this movie, and also that he couldn't read - put Valentino to shame in the adorable factor!!!)

It would be easier to mention movies of Ty's that I didn't like (there are only 3 of 48)