I had a few people ask me about strapless bras and what brand/style I prefer to wear but to tell you the truth, I can't stand strapless bras. I have never found one that doesn't slide down and is comfortable to wear for long periods of time. Since a few summers ago, I switched to bandeau bras to wear underneath dresses and tops that usually call for strapless bras and I love it! The fun part about bandeau bras is you can get so many fun colors so it can add a bit of an unexpected pop of color and it's not weird looking if it pops out. In fact, I try to make it part of the outfit most of the time. You can see how I wear it in this lookbook from a few summers ago.
If you are needing a bit of coverage, there are quite a few that do have cups built in. I actually really like these cheapies from Forever 21 and I always pick up a few different colors for the summer. Trust me when I tell you on a super hot day, these are so much more comfortable to wear than a regular bra. Once you try it, I'm sure you'll thank me! :)
I like how they paired it underneath a sheer top like this. I'm not brave enough to wear it like this, well maybe on vacation on a resort where I wouldn't be seeing many people :) But I do think it's a cute option!