Rainbowfish! Mine swim against the current of my Fluval all day. Its like a treadmill for them, lol. Hmm, I'm thinking more like regular-sized, tough rainbows like the australian mixes or boesemanis. Danity rainbows like threadfins aren't big fans.
Hmm, if you're looking for something original, then fish like freshwater flounders or "chinese butterfly" loaches love high flow and aeration. And yeah, plecos benefit from the extra oxygen. Sucker-type fish are developed for strong water flow, afterall.
Most fish except labyrinth fishes enjoy current though. Gourami-type fish tend to get thrown around by strong flow, a bit.