Well, I don't enjoy too much anime, so I'd prefer live action movies. Anyway, the only games I see fit for a movie would be PSII and PSIII, though PSIII would have to choose a path, unless it wanted to become some of those crazy movies with alternative storylines running in parallel.
PSI could be adapted with changes in focus, like focusing more on Lassic doings, background things, less on battles (only key battles). PSIV has a plot too shallow and infantile, so a major reworking would have to be done, cutting all the useless emotional references to other PS and the humorless humor. After all, who'd want to watch a series with a serious and deep installment (PSII) and a cliché children manga (PSIV)?