Most Comfortable Sofa...  

Malmo, Moroso
Malmo, Moroso
http://www.designdictionary.co.uk/en/urquiola.htm

Least comfortable...
Irving Harper's Marshmellow sofa vs. Charles and Ray Eames' Sofa Compact.
What'd'ya think?

Togo by Ligne Roset
My friend has these, they truly are incredibly comfortable, perfect for lounging.
SUPER COMFORT!!!!

I like the Ligne Roset...
I like the Ligne Roset chairs. Also I've read that the manufacturer uses environmentally friendly methods of production which is a good thing.
Between them I think that Malmo is suitable for a movie room best, as it is more compact and solid, and it doesn't get messy.

Qualifier
I thought you had qualified it with "looks fantastic"- those Ligne Roset sofas may be comfortable, but they look like some kind of metamorphosing caterpillar. A friend of mine just bought this one and its a-mazing! The shape is a little basic but its really deep and cushy and down filled. I dont love the color she got it in (blue gray) but it comes in a bunch of different colors. I know, I know its from the big red Goliath, but it really is a great sofa. Best of all its not flashy enough to distract from her vintage pieces (she's an eames addict like me 🙂
http://www.dwr.com/product/categories/seating/sofas/reid-sofa-84.do?sear...

If you like it square I...
If you like it square I advise you to get this or a similar one from Driade
http://www.designdictionary.co.uk/en/astori.htm

Steelcase
Believe it or not, vintage Steelcase sofas are pretty damn comfortable. They are basically vintage KNoll knock-offs. But they are made extremely well. You can usually find them for 1000-12000 in pretty good shape. I got a free one a reupholstered it and it has turned out great. If you are a mid century junkie who can't afford a Florence KNoll sofa, this is a great item. I am usually opposed to knock offs. I have really enjoyed my Steelcase sofa though. And it is lightyears more comfortable than the Eames sofa I used to own.

I've never seen a sofa better...
I've never seen a sofa better than Malmo. Just look how nice, and it isn't boring at all like the other sofas are... I love that...

I like whitespike's sofa,...
I like whitespike's sofa, stylish and looks comfortable 🙂

Isn't the La Corbusier
sofa comfortable?

Corbusier sofa
Not really. The back is EXTREMELY low. You have to kind of sink into the corner for it to work.

I think we are guessing too mu...
I think we are guessing too much. We don't know anything about how sammyman's movie room looks like. sammyman post a picture of the room !!

I love my Neo...
Comfortable, stylish. There are down-filled duvets over foam cushions. The cotton upholstery is removable for cleaning and simple enough that I'll be able to make my own replacements. An everyman's Citterio Charles.

How comfortable is the Eames...
How comfortable is the Eames Sofa? I always suspected it was high on looks and low on actual comfort. More like seating for conferring rather than couching.