I've rewatched Interstellar a few times since it originally came out, with one of those rewatches being quite recently.
It's such a phenomenal film, and definitely high up in my top 10 all time films. I've yet to see a Nolan film which I didn't enjoy, but there's just something about Interstellar that elevates it beyond his other works for me. I think it's how it deftly combines the sci-fi aspects of the film with emotion and the whole family angle - sometimes devastatingly so.
I remember going to see it in the cinema and thinking it would 'just' be a space movie with some clever Nolan angle, and it was so much more. I can also appreciate how it attempts to take a more realistic approach to the space elements than most sci-fi films do - I'm not saying it's always successful in that endeavour, but Nolan certainly put the effort in. Even things as minor as the lack of noise in space attribute a huge amount to the overall tone and atmosphere (no pun intended) of the space scenes, this eerie and deathly silence in the deadly vacuum of space - whereas most other sci-fi flicks have laser noises in space battles, engine noises from the spaceships and so on.
The performances of the whole cast are fantastic, but McConaughey in particular is the glue which holds the whole film together. I only found out recently how they did the scene where he watches the messages from his kids as they grow older - they were pre-recorded by the actors without him seeing them, so when he sat down to film his emotional response, that was a very real response as he watched these messages (in character obviously) for the first time.