Base cap is probably what you're looking for. If you wanted simple, you could also use 1/2" quarter round, as another suggestion. If you want more detail, 3/4" panel moulding would be nice... (if you want some illustrations, check out KD2111 on pg 16 in
this catalog. I use that moulding a lot.)
You might be able to find something similar at a millwork supplier in your area. (but it's probably not a big box item)