I'm running Mame with an ArcadeVGA and a scart tv. And I live in Denmark, which means that my TV natively runs at 50 hz. I'm going to state what I think are facts and the you people can set me straight if I have got this all wrong:
Given that my PAL tv also supports NTSC scan rates - 60 hz - then it makes no sense to choose refresh rates that aren't either 50 or 60 hz because the tv doesn't support this and games wouldn't run perfectly smooth (I know running at a non native rate would influence the speed of the game, however). To be able to utilize scan rates that are a little off 60 hz, one would need a multisync monitor and not a tv.
Or is a tv kind of multisync, say between 50 and 60 hz?