Dil, it's not because Season One just came out and you're feeling that anyone who lists it as their favorite is doing so simply because it's the only season they've seen in it's entirety?
I've seen, and I have, all five seasons in their entirety, and Season One is still my favorite. It does seem more 'nostalgic', but that's a big part of what I like about it. Yes, a lot of parts are unpolished, and the show clicks only on a week-to-week basis, but it has a lot of charm IMO and I love the look of the season, scenery-wise, how it goes from looking very 'nighttime' and like it's taking place in the theater to very 'daytime' and looking like it's taking place in the sets (mostly outdoors) in which the various acts take place, and back again to 'night' and 'theatrical'. It just holds a special place.
Season Two is close behind, though, and in terms of week-to-week and overall quality, energy, color, humor, and character I'd say this is probably the best season, the one that 'clicked' best even in it's lesser entries.
David "Gorgon Heap" Ebersole