I have some platies and I'm wondering what fish would get along with them.
Pretty much any peaceful tropical fish. Platies are great community fish. What size aquarium?
You have lots of options. What are you considering?
I have had albino cories in with mine with no trouble. Also, a dwarf gourami; although once they started having fry left and right, he became aggressive due to crowding (also was very good at keeping down the number of fry).
I probably wouldn't put in another livebearer though, as they will fill your tank super quick between them (this would mean no guppies, swords, endler's, etc.).
Hope that helps!