I was on F1 till May and then OPT from June to September. H1b active since 1st October.

I have been told by a few people that I can file as a resident or a non resident?

Now I was wondering if there any advantages of filing as a resident?
(I have some interest income which will not be taxed if I file as a non-resident but I am not sure about other differences such as standard deduction amount)

If you are married, there is a BIG advantage to filing as a resident because you can file a joint return.

Joint returns are NOT allowed for non-resident alien returns.