I get compliments on my eyes and eyelashes.
I like my eyebrows, personally.
Probably more than is justifiable, but I’ve gotten enough positive feedback on the following things that I sort of believe them:
My hair- I’m over 40 and have only 1 gray one, at the temple, and otherwise it’s rich dark brown and plentiful.
My shoulders- they’re broad for my frame.
My butt.
And OK, I’ll say it- my dick. It’s not exceptionally long or anything, but it’s got girth and a nice shape to it. It’s received compliments.
This cracked me up. The cleavage might make it hard for you to pass yourself off as a man, though. 
My eyes. Really bright, clear green. I have people ask me if the color’s “real” all the time.
My eyelashes. They are long and full.
My brain. I always seem to put out this air of someone who knows stuff and can do anything well. I’m very vain about that. I adore it when friends compare me to Martha Stewart or ask me to bring a dish to a party.
Hmm. On re-read, that might have come off strangely. What I meant was that a smile brightens up anyone’s face.
(And though I’m not vain about anything in my appearance, I do have insecurities about it. So I try smiling.)
Honey, feel free to feel vain about your lovely breasties.
My butt. And on occasion, my dick. I’ve been told consistantly that I’m hung like an elephant. I don’t think I am, but all I have to compare myself with is guys in porn movies.
tdn: single-handedly boosting female self-esteem since…well, at least 2003. 
Hear Hear!
My eyes: usually kind of a blue/green mix, but they can go bluer or greener depending on what I’m wearing. Or crying. That turns them clear cat-green. I haven’t found a way to get that look without tears and bloodshot part.
And while I’m not really vain about my face, something about the combo of oily skin, freckles, and rounded features means that people never believe how old I really am (40).
My eyes - they are a great shade of light olive green. Very unique.
My hands and fingernails. My hands are small and feminine, and I have long thin fingers, and my nails are long and very strong and look like a fake french manicure, but they’re not.
My feet: my boyfriend loves them! They’re small and feminine, and very cute, he says.
My teeth are perfectly straight and have a great shape to them, and I’ve never had braces. I’d just need to get them whitened and they’d be perfect.
I’d love the rest of myself if only I were 30-40 pounds lighter 
When I’m thin, my body is great. I also used to love my hair, but it’s getting a lot of gray in it, so it’s a pain in the ass because I have to color it, which is expensive, and the coloring changes the texture and damages it, so it’s not as healthy as it used to be, and I can’t keep it as long as I used to.
My eyes and their immediate surroundings (eyelashes and eyebrows… I’m a bit too proud of my eyebrows) are quite nice.
My breasts are frequently described as “huge”, “massive”, or “gigantic”.
I sing very well.
Also, this isn’t something I probably should be vain about since most people think it’s really weird, but my buttcrack doesn’t start until really far down. I never have to worry about plumber’s crack or coin slot dryness, because there is no way it’s ever exposed unless my pants around practically around my knees. Uh, sorry, that may have been a bit TMI.
Hey, it’s from the heart.
I think it’s my calling in life to help women to feel good about their bodies. It’s a calling that has… benefits.
I know! It’s the fatal flaw in my otherwise cunning plan. 
My eyes are large, blue-green, and expressive. My hands and feet are nicely-shaped and fairly well-kept. And my boobs are…nice. 
I’m not particularly attractive, what with being short, having acne, and straight bland brown hair. However, I am more ripped than pretty much everybody else I’ve ever met, except my dad.
Also, my Backspace key just fell off. Something tells me this is a bad thing.
I’m vein about absolutely nothing.
Other than having a (from extremely low to moderately) low self image, I… yeah, that’s pretty much it.
I have great skin. It’s clear and smooth, and I’m 30 and don’t have a single line or wrinkle in my face (my secret: sunscreen 365 days/yr, every year, since age 15).
I am vain about my skin. Great texture (all my life) and even at 48, I still don’t have wrinkles at all. Every single person who has learned my age in the past 15 years or so has been shocked, and they generally guess I am 10 to 15 years younger. I have seen dermatologists for skin cancer on my wrist and even they say I have great skin.
If anything it’d be my hands. They’ve taken a beating over the years and have some scars and are often chapped and dry in the winter. Otherwise, they are slender with longish fingers and due to a life of manual labor and hobbies that demand a lot of hand strength they have developed a veiny, sinewy, muscle-y look that I like.