My boyfriend likes to stay up later than me - either reading on his forums or playing games (WoW-World of Warcraft and the such). What works for us is we spend some time together watching a video or something before I go to bed. Then he comes to bed and lays with me and we talk for awhile or do whatever. Then when I'm ready to fall asleep he kisses me goodnight and goes back downstairs. This works for us.

We were also fighting about him spending more time on the computer than with me, so this is how we have made it work for us. Good luck.