I like pocket (also called pouch) slings. They are really easy to use.
I also have the ultimate baby wrap, it's a PITA to wrap up, but once you've got it on it fits GREAT and is so comfy. It has a little stretch to it too so that's nice. It's gentle on my shoulders. I can't wait to try it with a tiny baby!
I have a baby bjorn from DS's early days and that is ok. I've since heard that it keeps the baby's hips at a bad angle so I don't think I'll be using it much.
I just bought a mei tei off the TP and that might be my new favorite. I put my DS in it this morning to test it out, he weighs around 36 lbs. I had him on my back and it wasn't too bad. I think I could actually carry him around like that for up to 30 mins at a time. I think it would be a really nice carrier for a smaller babe.
I also have some ring slings, one cotton and one solarveil. I like the solarveil because it offers protection against the sun. It also makes a good sling to wear in the shower or water. We live in FL so sun protection is important. I used it as a blanket for DS when he would fall asleep at the beach or in a stroller.
I had a nojo by Dr. Sears and hated it. It is next to impossible to pull those padded rails through the rings. I didn't use it much and ended up getting rid of it. I don't reccomend it.
I did have a baby bjourn with DD too, and I used for a couple months and then stopped. I know I want to try a fleece one....now if I could recall the name!!