Name the Artist: Monster Mash Bobby "Boris"?

Questions

"If I'd known I was going to ---------------------------, I'd have taken better care of myself."- Eubie [James Herbert] Blake?

"If I'm not back in five minutes, ----------------."- Ace Ventura, Pet Detective?

"If it weren't for --------------, we'd all be watching television by candlelight."- George Gobel?

"If it weren't for -------------- I'd have no sex life at all."- Rodney Dangerfield?

"I can never forgive God for having created the ----------."- Peter Ustinov?