Some Avon stuff is really good. I'm a huge fan of the Mark line because they do a lot of really fun stuff and it doesn't exactly break the bank. The Outlet is insane, I can spend so much in there when you can get good items for a buck or two. As far as the mainline, I love the Uplifting and Daring Definition mascaras as well as the 10% vitamin C serum which really helped my face. The lipsticks are as good as my Lancome ones and the Glimmersticks eyeliners are pretty nice too. I've heard that most of the skincare isn't great though.
I adore the Ultra Luxury eye pencils in dark brown and eggplant. The brown especially is super blendable and soft. The Glimmersticks have something in them that makes my eyes cloud up. (Though maybe it's the just the particular blue one I have).
I used to wear the Glazewear lip glosses, which were pretty long-lasting.
I'm also a big fan of the nail polish. Most of my favorites are discontinued now, like the color-change FX and Rainbow which were really long-lasting and absolutely gorgeous. They still might have the Mirrorshines, which were AWESOME metallics.
As for Mark, I'm a big fan of the Kiss Therapy Rose Balm, Glo Baby Glo glosses in Peekaboo (fav!) and Honey, and the liquid eyeliner in Cleo. I've tried one other liquid eyeliner, Lilith, but it clumped up too fast. I might purchase it again since I'm not entirely sure I kept the lid closed tight enough and I really liked the red-brown /bronze color.
Right now I'm "testing" the i-Sheer cream eyeshadow, which is very sheer and blendable, and the snap-on Gel Blush in Pink Pearl. So far I'm lukewarm about it...it dries quickly and requires a lot of blending so it doesn't look like a stain.
The Jill Dempsey for Avon Professional Kohl Eyeliner is amazing! I have a couple of shades and they are so smooth, so they create an easy smokey eye plus they actually don't smudge or smear when you wear it throughout the whole day.