I find bras without an underwire a lot more comfortable, for obvious reasons. Of course, if you have large breasts you may need the underwire for extra support.
I tried them and now i find it hard to go back to wearing padded bras or ones that have underwire. It's almost as wearing a bikini top.
The pictures are from this local brand called Amor Latino, I know this is not available for most of you, but i wanted to share it anyways. They have the most cute pieces. I'm a bit addicted, i may own all the stuff they have on the store