Reputable ones. The ones with great alumni and that look good on your resume. There are so many schools that can teach you what you need to learn. That said, the only ones people looking at your resume are going to care about, are the ones they recognize.
When I first moved out here, I got an agent as a mentor. She gave me a list of the top 5 acting schools in town. Through the years after following her advice, casting directors have always commented on the reputable schools where I've trained.
If you have questions about what schools are reputable for your classification, call someone who reads resumes all the time and see if he/she would be willing to speak to you about it for a few minutes.
Note: some recognizable schools are: in Los Angeles (USC, AFI, UCLA, CAL ART, GROUNDLINGS, and more) NY, (NYU, SUNY Purchase, and more) and Chicago (The Second City...I know there are more that I'm not aware of). There are many recognizable film/theater departments at colleges in various states as well. If you have a school you'd like to add, put it in my comments. Thanks!
For more tips and articles by top entertainment industry coach, The Greenlight Coach, visit www.theGreenlightCoachBlog.com