What live bearer should I get?

[Shootemz]

It's a 20 g cycled everything at 0 with 6 bronze corries and a flame gouriami, I was thinking about guppies, or platies, or swordtails, but not Molly's because I heard they get sick easily. Any suggestions?

[sheamurai]

I haven't experienced mollies dying off any worse than any other species of livebearer, but really, aside from size, there's nothing to choose from among the ones you have listed.
As you have a smaller tank, I would stick with smaller species, either guppies or platys - and endlers are cute, too. With a gourami in the tank you won't worry about fry, so make sure you get one male for 3-4 females so no females get pestered to death.

[steeler1]

+ 1 on the above advice.