What's the most comfortable and still binds well (gets you the flattest)? I like underworks but the comfort is starting to get to me - they get itchy and irritating I guess.

I'm a little guy as most of you know (5'1 and 105lbs or so). Binder size is an xs but because of my shoulders I'm starting to fit a small. That's all irrelevant.

Personally, I put a compression shirt under my binder because of the itchness....and it works for me.  I have been wearing a binder every day for over three years now and I guess I am just kinda use to it.  My son who is also small like you puts an xtra small sports bra on and it binds him enough

Personally, I hate underworks binders. If you've tried something from lesloveboat, you know why. Yes, it's more expensive, but I guarantee it will last much longer, wear less, and be much more comfortable. I'm living in Egypt currently and was concerned about sweating profusely. I was able to get a couple binders from them that provided the ventilation I needed, as well as keep me comfortable enough throughout the day without feeling too much pressure. If your small chested though, I'd just wear a compression shirt if you can pull off having pecs.

i wear a medium underworks tri top and i have never had a problem with it i cut the bottom of of mine because i found it uncomfortable but now its good.

Lesloveboat, all the way. I have a zip-up vest binder and I will never, ever, ever, ever go back. I wear it every single day and it's shown 0 wear-and-tear. I would recommend these things to anyone and everyone--oh, and I'm a relatively big guy, chest cup is only a C but I'm pretty wide and have a little flab and these work great.

I think the velcro binders from Les Love Boat are the most comfortable. I have the ones with the mesh back which do keep you cooler in the warm months and of course they're totally adjustable so you can have them on as tight or as lose as you want.