poptimists | Imitation And Limitation

During yesterday's DUFFY DUST-UP, there was a bit of talk about whether it matters if someone is riding on the market coat-tails of someone else.

datura800 and

girlboymusic both said things to the effect of "well that's just how the industry works, it's hardly a surprise". And I can see their point - when boy bands and girl groups are big, pop fans look for the elements that make each boy band interesting, rather than dismiss them a priori as a market response.

I'd like to take the debate wider and ask - when do you and don't you mind imitation and bandwagon jumping? Are the originals always the best? Does it make a difference when the trend (as with the Winehouse one) also has a relationship to much older music? What are some of the most blatant rip-offs you've enjoyed?