I'm 5'5 115 lbs and got size small. It's a little big and way too long (nearly past my knees!) but still wearable if I hem it to be way shorter...

 The best thing this dress has going for it is the cut should be really flattering on most people (it's A-line), the fabric of this dress is also stretchy and the straps are adjustable so you have a lot of leeway (it also runs a little big).

What I don't like about it is the print. I found it downright ugly in person, but I'm not a big fan of flowers in the first place (I liked how bright yellow they are in the pic but they're more brown in person). It's also too see-thru on the top (in a cheap i-bought-it-at-Ross-for-$3 kind of way, not a sexy way). I'm sure this could be fixed somewhat by wearing a sports bra underneath.

The one I got also has a weird defect with the print (one of the flowers has a white smear around it from where it messed up, I guess). Next time I dye anything synthetic black I will probably throw this dress in with it.