Epic Riff: A lot, but "Smoke on the Water" is the most famous example.
Germans Love David Hasselhoff: A strange case. Even though the band never enjoyed more than modest popularity in the US, Mark I was more popular there to the point where UK fans thought they were American, to the point where they earned 10 times as much on a US gig compared to a UK gig. Today the band is more popular among European audiences, especially in countries formerly of the Warsaw Pact.
Replacement Scrappy: Steve Morse, if you're a Ritchie Blackmore fan. Also Tommy Bolin when Blackmore left the first time.
But Bolin was a great guitarist. He could've gone pretty far if he hadn't suffered Author Existence Failure.
David Coverdale , Glenn Hughes and Joe Lynn Turner for Ian Gillan fans.
And also Ian Gillan if your a Rod Evans fan.
The infamous 'Bogus Deep Purple' lineup of 1980. And how.