Hi, can anyone help me. I remember playing a game a few years ago (probably early 90's), on my sega megadrive. It was an RPG involving a prince travelling from town to town, journeying through dungeons and the like. I also remember big boss battles which were displayed differently in a side on view. Any help on this matter would be great as I remember really enjoying this game and would like to play it again.:)

Do a search for these titles:

Eye of the Beholder
Lunar: Eternal Blue
Lunar: Silver Star
Shining Force
Popful Mail
Dark Wizard
Vay

These are all RPGs for the Sega CD/Megadrive.

But you mention a prince, and if that's accurate, it's most likely going to be Vay.

Check Vay here - Sega CD Reviews