If you don't want to fly a trainer, lots of planes work well on floats. Astrohogs are great. Ugly Sticks of whatever variation you want. I have been flying a Morris Jerry's Little Boy. The Moris Profile planes work well.....and the power-to-weight is so great that they take off easily even with Gee-Bee (ptooey) floats.

If you want to be brave, and crave scale, there were Spitfires mounted on floats, and at least one Wildcat. No Mustangs. THere was even a prototype P-38 on floats, but the modifications required were so great it was deemed not worth the trouble.

Grab your most comfortable sportplane, slap on some floats, and have fun.