[Vermont Lt]

I would think Irving Berlin, Porter, and the Gershwins are at the top of the list. Even George Cohan.

Pop writers? Simon is up there, as is Micheal Jackson (as much as I hate to admit it.) Even Neil Diamond and Burt Bacharach (sp) are on that list.

I guess you would need to set some parameters (era, money, etc.)

[Scoutmaster]

If imitation is the sincerest form of flattery, the Gershwins, Richard Rogers, Johnny Mercer, Cole Porter, and Bob Dylan are at the top of the list. Here's an up-to-date list of number of artists that have covered a songwriter, number of songs that have been covered, and total number of covers.

IMHO, Brian Wilson is leagues ahead of Michael Jackson.