Without Nirvana being influential, you wouldn't have ever had the Foo Fighters (any many other bands), and I'm a big fan of both.
Nirvana only really got going into the mainstream when they ditched Sub-Pop, and started working on Nevermind, but that wasn't going well until Grohl got on board and Butch Vig producing etc. Without the latter two they wouldn't have been anywhere near as big and that was 90's onwards. Not saying Bleach wasn't good mind, as it really was, but it was never goign to be mainstream or influential.
I don't know many who list Foo Fighters as their favourite band, especially not after There is Nothing Left to Lose, which was terrible compared to the Colour and the Shape or the self titled first album. The funny thing is Dave did everything on the first album, and I think they got picked up without relying on Grohl's name as he sent the tape out anonymous.
Oasis is a fair shout too, especially for the UK, moreso than Radiohead I think.
I don't think Radiohead really influenced many bands, as nobody could match what they did, but most people into rock appreciated them, and more the UK than anywhere.