Krillin is the most skilled fighter. He seemed to get the most praise in the battle vs the Saiyans, when he was likely weaker physically than Tenshinhan.
If it's no-holds barred, Tenshinhan because of the Kikoho. Kuririn has the Kienzan, but that's far easier to dodge, especially if Tenshithands uses Taiyoken before launching the Kikoho.
Tien due to having the strongest techniques, plus is more experienced at flying. Krillin ain't all that against an opponent that is stronger than him, and Yamcha hasn't trained enough.
Tenshinhan because of Super Kikoho which is easier to land than a Kienzan. Kulilin might be able to get Tenshinhan off guard while he's fighting Yamcha though. Tenshinhan wins 4-5/10 times