In real-time RPGs, I like Red Mage type characters who can do a bit of everything. While I put the focus on magic, I like to have a decent physical attack to fall back on should the need arise.
I really liked the characters in Tales of Graces because of this. All of them have useful A-Artes (standard attacks) AND B-Artes (magic and such), instead of just useful B-Artes and crappy A-Artes (or vice-versa). Richard was my favourite. He has good single-target spells, good AOE, a spell that can heal himself, some of the most powerful skills in the game and fast, moderately powerful rapier artes. He sacrifices some stats in areas like defence, but his overall utility is high.
If things are NOT real-time, though, and a player's skill is not as big a factor as a character's stats, I tend to go full mage. KILL EVERYTHING WITH FIRE.