Probably not at all in the States, but I'd consider (You Drive Me) Crazy a huge hit here in the UK - it's STILL played pretty regularly on 'cheesy' nights and '90's nights' (even though it's not 90's, riles me up!!), I hear it more on nights out than BOMT to be honest...

(You Drive Me) Crazy was huge here, and it still gets played at times :o

"Baby One More Time", "Oops!... I Did It Again" & "Toxic" are the main ones. But I think "Everytime" is also a signature hit because of it's nearly banned video and the fact that is apparently written about Justin Timberlake. And maybe "Me Against The Music" but that's only probably because of Madonna