Welcome to AA (always makes me think of Alcoholics Anonymous, Aquarist Anonymous would work haha)
I'm doing a community tank with gouramis, ram and South American dwarf cichlids, and I have a couple tetras and rainbow fish. The possibilities are practically endless, but Sillyfishies mentioned a good combo for a 20 gallon. I haven't added any shrimp or snails but have been thinking about adding some shrimp.
Again, welcome! Hope you enjoy! I've found the site very helpful.