I'm not an uber Pink Floyd fan but they are without a doubt one of the best rock bands ever. I really like the stuff they did with Roger Waters and after he left I just kind of listened to whatever they had out on the radio or whatever.
This album is one of my favorites from any band of all time. I know it's referential to Syd Barrett but really the lyrics are quite universal to me and reflect one's own life experiences easy enough. The album has a flow that weaves each song effortlessly from start to finish.
Yep, this is one of those must have albums for me. Great stuff.