What Kind Of Fish Can I Get For A 25 Gallon!!!

I 'second' the vote for the Red-headed Goby. They're colorful little fish and also a 'cleaner' species, so they'll play doctor with your other fish.
They also have some of the spookiest eyes I've seen on a fish... almost like something alien. IIRC they only get around 1-1/2-2" long so you won't have to worry about it outgrowing your tank.
This will probably the next fish I purchase for my 55g reef.

Oops... I guess I stand corrected. I thought I had seen that Redhead gobies were a cleaner species, but according to an article at reef central they aren't.
Ya learn something new every day in this hobby...