Well my Zebra Danio and Cherry Barbs absolutely love playing in the current, the faster the better for them, the cherries to a slightly lesser extent then the zebras but both love it. My Harlequin Rasboras also like playing in the current, but not as much as the others. Finally, as odd as it may seem, my Pear Gouramis and my Betta can also be seen playing in the current on occassion, and they are not suppose to like current at all. But if you are looking for a really playful fun to watch fish that loves currents you can't go wrong with the Zebra Danio, and if you are in the US (other thatn California) you can get Glo Fish, they are Zebra Danio but due to some fancy genetic work they are coloured bright green, yellow and red.