Zebra Danios? Boooooorrrrring. At the risk of sounding like a broken record, N. multifasciatus.
Cons: They will be very shy untill they produce a nice colony (takes about four months). They are expensive (not entirely a con, see pros for explanation) and somewhat hard to find. They require a slightly different tank set up. Sand is a must. You will have to beg and buy every empty apple snail shell you see in every petsmart you go into.
Pros: After four months you will go from two shy fish to 15+ fish that are constantly moving sand, digging pits, displaying to each other, and picking at anything that appears even remotely edible. I sit down in front of my 20g long multi tank (15+ adults and numerous fry) and literally lose myself in a buzzing metropolis of activity. They will reproduce like crazy on simple flake food (no bbs, no grow-out tank needed). Remember the expensive part. Now the tables are turned, and you have sub-adult multis you can trade for food and supplies at LFS.