I'd add
Gawain,
Tristan,
Isis (I didn't think it was very real-life-ish, but then I met one :P ),
Orion,
Jason,
Pollux (maybe), Galad (more useable than
Galahad imo..?),
Athena,
Artemis (pronanly mn),
Morgana,
Isolde,
Apollo,
Hecate, and
Emrys.