I always used the ones that say High Bias 70 (symbol that looks something like a backwards y) s EQ, High Position Type II Super Avilyn CrO2 (Chrome). I'm reading this off a TDK SA90. They sound much brighter and crisper than the "Normal" type.
A good source of them is garage sales and flea markets, where you can get them at giveaway prices. They usually already have music on them, but you can record over it. If the punchouts on the spine have been removed, just put a piece of tape over the hole. Make sure they look clean and nice, and check for signs of heat damage (curled tape), make sure the little piece of felt under the tape is there. Set your deck for the CrO2 position. I always pushed in the Dolby button, too.