I like a memory foam pillow for my head. It has a ridge that fits under my neck and a dip for my head, so my neck gets plenty of support. I have a shredded foam pillow that I use for my knee when it aches. I agree with Sandy - you're going to have tons of different opinions.
IKEA has lots of different pillows designed for back sleepers, side sleepers, stomach sleepers.... I didn't like any of them because I found they were all way too flat for me. But for those who don't like poofy pillows they may work well.