I like it! And here you are saying you're not that good. Nonsense I say, nonsense!
I think I like your eyes on the first two best. You're really good with getting them to look shiny and really getting the different color contrasts that go on. These do look professional. My personal favorite is the second one, since I like the proportions and it's just an appealing picture overall.
I do, however, have two critiques. My first one only applies to the chibi pictures, and that is that I find the heads to be a little oversized. It's just personal preference, but the heads are too big for my tastes. My second critique is shading. You did a bit of shading with the second one, part of the reason why it was my favorite, and it adds a lot to the picture. I would recommend giving it a shot with all of your drawings in the future, and they could come out even better.
I'm not much of an artist myself, but everyone has something they can add, so there's mine. I could be way off with my critique, but there's my two cents anyway. Don't feel bad about your art. It sure is nerve-wracking when you post it for the first time, but be more confident with it, because this is really good. Nice work!