I have always kept goldfish in my community tanks. Other than a couple getting beaten up because a pair of Dempseys decided they were ready to breed, I've never had any problems with having them in a tropical tank. Oh, and I caught one eating one of it's smaller tank mates too, but that's fish for ya.
If you do decide to keep some goldfish, just remember they grow big and fast.
From your other questions, you're wanting a peaceful community tank I'm guessing. There's all kinds of possibilities.
Any of the Cory catfish
A small pleco, like the gold nugget, or rubber lipped
A school of neons, black neons, glowlight tetras, or glo-fish (http://www.glofish.com/)
Some guppies, platties, sword tails or mollies (all good at reproducing)
A pair of Kribensis(if you've got enough decorations and stuff if they decide to mate)
A betta, paradise fish, or small gourami
Glass fish (not the painted ones)
Killifish or Rainbowfish (if you can find them in your area)
Goo Obo Gudgeon (interesting little fish)
Celestial Pearl Danio (or Galaxy Rasbora, it's name was changed. A tiny little fish, but they look great in a group)
This is just a small list of fish.
One example of fish might be something like this==
2 Neon Blue Dwarf Gouramis
6 Panda Corys
1 Gold Nugget Pleco
6 Congo Tetras
6-10 Celestial Pearl Danios
A pair of German Blue Rams
That gives you fish that cover each swimming section of the tank, a variety of color, and still leaves you room to add a few more or different fish.
Look around at the stores near you, and see what fish you like, then do a little research on them to see if they fit what type of tank you want.