If you like wrecks there are some great one's around Sharm, a couple off Tiran Island which is just off the coast at the north of Sharm. There's also the Thistlegorm, probably the most famous wreck in Egypt for diving. Look into going on a livaboard for a few days, some are geared more towards wreck diving. There's also Ras Mohammed marine park which has some fabulous dives.
I've been to Sharm about six times and love it, if I'm not diving I can easily spend hours snorkelling...ending up with a very strange looking tan though.
I'd also look at Marsa Alam which is a lot less touristy. I've stayed at a couple of hotels there but my favourite place is Red Sea Diving Safari where you can book an unlimited dive package for the house reefs...great value plus you are not tied to a schedule, they also do truck trips to other dive site along the coast, or you can can get the rib to drop you further along the reef. Also Elphinstone reef is only a rib ride away.
Have a look at Oonas Divers for Sharm and Marsa. I've dived with Sinai Divers and the dive centre at the Sheraton, both were excellent. You could check out the Yorkshire Divers forum's trip reports for Sharm as many of them go to Egypt both land based and on livaboards.
Oh yes, saw my first hammerhead off Tiran Island and my first oceanic white tip off Elphinstone..woohoo!
