I like the basic velvet tank leos (low scoop back) the best, in solid colors and also in designs, with the regular tank straps and also the double spaghetti straps kind (especially for the summer!). The back strap details, and the leos with one strap wider than the other may look good, but I don't think they're comfortable. Velvet shorts over leos look good and are comfortable too! :D
Velvet is nice because they're soft and you can worry less about transparency and the fabric being too thin.