Natu is good if you can play it right, but against a lot of Pokemon it becomes a liability. Magmar's also good, but its frailty and weakness to SR really limit it.
Nice... I think I ran into that once or twice. Really tough to beat if you don't know what you're doing.
Ah, the Perish Song abuser. Never seen one without Mean Look, but that seems interesting. Pity you have to pick between Prankster and Insomnia.