This thread is quite amusing - that people still have debates like this in the 2010s as if Oasis and the Stone Roses are still as important as they were in the 1990s!
I liked Oasis when I was a teenager in the 90s. However, the more I found out about music, the more I realised that they didn't have any attributes of a great band. Definitely Maybe is still a good album but their failure to innovate or match it on later releases is a poor legacy. All Oasis had that many other derivative britpop acts of the 90s didn't was that extra bit of swagger and posturing that won them a place in lad culture and lots of sales. Musically they are completely unremarkable. I can understand why people like them, but the same applies to the Spice Girls, who were presumably more commercially successful at the time.