A list from down under - but on the right side of the Tasman (figuratively and literally) ... So, since the title doesn't place any particular limits on the list, here's my pick for NZ:
Sarah Ulmer - three world records, world champ and olympic gold in pursuit all in 2004, plus a handy roadie
Brian Fowler - one of the best amateurs who never turned pro - despite what were reported to be some seriously good offers (in light of the "Clinic" threads, maybe he was the smart one??)
Jack Swart - absolute demon rider, could still kick many a **** - and he's in his 60's
Eric Mackenzie - one of the original hard men from down under to race pro in Europe
Julian Dean - ask Thor, Tyler or anyone else who's raced with him
Greg Henderson - former scratch race world champ on the track and a damn good roadie
Hayden Roulsten - another awesome trackie, plus overcome a major heart problem to get back into the pro peleton with Cervelo
Karen Halliday - points race world champ in 1990
Tino Tabak - actually Dutch, but moved to NZ in the early '70's and was a major force in building road racing at that time
Kashi Leuchs - NZ's most successful MTB racer - been a consistent top 10 ranked rider for years
As with any list, that leaves heaps of people out ... I could think of at least another twenty or so riders who could figure ... and I bet most of you didn't think that there were that many riders in NZ, total!!