as Femme says bamboo isnt that bad, I use a lot of bamboo and it all dries overnight on an airer next to the radiator. I really like hemp because its very slim, it takes less time to dry than bamboo but isnt QUITE as absorbent. Microfibre is the quickest drying but it can be bulky and it doesnt hold as much wet, its fine for daytime use you just may have to change the nappy fairly regularly to ensure against leakage from overspill. I also like the organic cotton, its similar to hemp on the absorbency and drying front.
A popular insert are the blueberry ones which combine and fold out for drying. They arent my favorite as they are bulky because of the microfibre but this will be less of an issue once my LO is bigger and can easily deal with slightly more bulk.
Hemp and bamboo inserts that fold out for drying (trifolds for eg) are great if you have to hang dry. Almost all my inserts are this type as although I do have a drier I prefer to hang dry as much as possible.