I like the Wowmeh body, but I haven't bought it because I really don't have any characters active right now that would be naked often enough to warrant the spent. It's great for players that do though, I think.
I'm still in two minds about the heads. Some of them can look great, and while I've seen some amazing avatars that use them, I'm not sure I'm ready to let go of making my own faces and using tattoo layers now that I finally seem to be not-so-terrible at doing it. I think for some people who struggle with sliders or don't want to put in the time it takes to not look like a freak with no chin, or like Desperate Dan, they're a good, quick fix that will always look at least passable. As long as you don't make your body way too big like I've seen a few times with that creepy kid-looking mesh head.
I own the creepy-kid-looking mesh head and the LOGO one, but I use neither.
I also own Lolas but don't use them. I think they look a bit silly on thinner avatars, and I generally like to make my avatars on the thinner side because I seem to have a preference for 'agile' characters. On that note though, there are boobs called "perkies" that are shapes as a smaller breast. They work with lolas appliers, but unfortunately the shading is all off (obviously) for the shape. I'd like to see these developed a bit more (they're difficult to fit) and more skin-makers making appliers for them.
Hands and feet are basically a 'must have' at this point I think, almost as much as mesh hair is. Suddenly the sausage fingers I grew to love are an abomination and walking on planks is no longer acceptable. But the slink ones are best - for female avatars anyway. The hands that come free with "TheShops" skins are so bad i just bought Slink and tinted them. Saying that, there's a whole load of issues with The Shops business model - I can't see myself going for a skin from there again unless they start making appliers.
I like the ears - on men though, usually. I've seen them on a couple of chicks and they look good, but mostly they look good on dudes. The Skinnery ones are the best from what I can tell.
Despite mesh eyes being higher resolution in terms of textures, I still find myself using system eyes. Mesh is handy for the multitudes of people afflicted with heterochromia around SL though I guess. I think this is just laziness on my part too. I did play a one-eyes character and used a mesh eye and a sclera base, so again it opens up options for character customisation.
Phat azz - no.
Mesh lashes - no. Probably an issue with my viewer but they always look like my 13 y/o little sister when she puts on six layers of four different mascaras over three hours. I like redgrave's lashes too much anyways.
Mesh nipples - what I use instead of Lolas, because I want fancy tatas too. I love the ones from lotus. They drip and squirt milk - praise the kink community for our role play props.
Mesh pubes - because I like pubes.
PENIS! - good lord there are too many controls on that Aeros HUD. But Aeros is the way to go I think.
Did I miss anything out?