Honestly: Do something different. Do something that shows you know me. Don't follow a gift giving guide, don't follow the advice your girlfriends gave you over dinner.
Sex is sex. Yes, it's wonderful.. and I realize I may be the ONLY man to ever say this.. but I'd rather have something heartfelt and unique. I, as a man am tired of people thinking along the lines of "Oh, just give him a blow job and piece of ass.. He'll love it"
I realize this isn't the most helpful answer as every man is different, but find out what the man you are buying for really enjoys. For me.. I'm a photographer. If a woman handed me a box full of prints of my pictures or one of my pieces custom printed in a nice frame.. I would never forget that.
Sexually I would like to have my partner do a strip tease, masturbate with some of our toys to have a few orgasms - then tie me up, tease me for a 1/2 hour or so - then set me loose for a DP scenario with me and one of her favorite dildos.