Some disclaimers and context: I'm pretty neutral on Matthew McConaughey. Some people aren't, that's fine. I'll try not to admit to seeing any of Anne Hathaway's other movies, even though I have. I like Christopher Nolan movies in general.
And I like spaceships. I really really like spaceships.
Bad stuff first: There are some plot head scratchers, and overall it's kind of a cliche'd plotline. It's a very long movie. It's a very dialog heavy movie in places.
That being said, the nerd in me wants to see the 6 hour director's cut and get a look at all the stuff that was done but couldn't be made to fit (because you just know there's a ton of stuff on the proverbial cutting room floor).
Good stuff second: The space scenes are breathtaking. Period, end of story. And the gfx were done WITHOUT a SINGLE green screen (crazy in today's Hollywood). Matthew's performance is good, maybe great. Anne Hathaway has a tough role to fill as the non-love-interest female costar, and although some headlines/reviews had her "miscast" I think she did a solid job given how the character was written. The supporting cast is huge (damn near half the cast of Ocean's 11 shows up) and was money well spent. And the science behind it is (mostly) real - see this Wired article to help appreciate it.
Jedi mind trick: You want to go see Interstellar.
I think that the movie is worth seeing on the big screen, preferebly Imax. It won't have the same impact, depth, and scope in your living room. There are some scenes where premium audio are really worth it (seat-shaking bass during rocket engine sequences, etc.).
We intend to go again.