Some stuff I did when I made a game using GameMaker last year:

Epic scenes will make it good. (think The Landing from FF8)

Good music that doesn't get people turning down the volume every time its up. (like the main FF theme, yuck)

Also a great atmosphere/setting to play in.

Enigmatic or characters with heavy backgrounds are cliche though they always bring talk about a game (Magus from Chrono Trigger, Zack from Crisis Core, etc)