For me it's the Invincibles because of the players they had and the football they played. That Chelsea team was not as easy on the eye as the Arsenal one. Arsenal had the right mix of creativity, skill, flair, power and defense. Plus the fact that no other team has managed to go a whole season unbeaten shows how difficult it actually is to do that. I might be wrong but as well as being 'invincible' they also reached the Champions League final in Paris but lost to Barcelona. So Invincible in the League and Champions League final is pretty good, no?
As for Man U, the team with Ronaldo etc was good, no point denying it, but their best team has to be 1999. The Treble and home grown players like Beckham, Scholes, Giggs, Neville's, Butt. Won't ever be done again!!
