I haven't finished Doom patrol yet (still need to get the third big trade) but I like it a fair amount. Some stories are better than others but it's really quite good all round. In truth, though, the best Doom Patrol related comic book that Morrison ever did was Flex Mentallo, which was, very simply, absolutely brilliant and a whole level above anything in teh main series. That gorgeous Quitely art doens't hurt either.
If you want classic '80s DC-verse Morrison, I cannot recommend Animal Man highly enough. It's his fitst work for an Americna publisher and it's still one of his best. The art is functional rather than noteworthy but Morrison's exploration of reality, stories and the way the two interact may not exactly be an original theme but the way he handles it is something else entirely. It has a slighty slow start but it's something like 25 issues in total so it's a very contained work. Also, along with the more meta stuff, he kicks ass on even the most basic storytelling levels too with good pllotting, great characterization and a surprising amount of heart to boot.