I like both bands, but I never really considered them to be all that comparable. I grew up in the 90's (graduated HS in 98) and played covers of both in garage bands as I play drums and guitar. Nirvana was lumped in with the Seattle scene and Sublime was a California band with their own sound.
I guess you could lump them together as genres of rock music, but it would be like comparing Jethro Tull to Metalica, when Jethro Tull beat them for best Metal song at the Grammy's. I always liked Alice in Chains, Pearl Jam, and Soundgarden better than Nirvana though when in came to the grunge stuff.