I like lami cell memory half pad. ( I think that's what they're called. If you search lami cell half pad on Google it will probably come out.) I don't like wool or sheepskin pads so this is perfect for me. They are really good quality my horse and I likes it a lot. But it is a little pricey.
Personally, I wouldn't go for the full memory foam ones as I think they start to compact after a while and they don't really provide ventilation. However they do like nice on the horse but can be really pricy! I'd recommend gel half pads, sheepskin or half pads along the line of eco gold however that's just a personal choice :)