Gosh that's so hard to choose! I love watching tv with him... it sounds totally lame, BUT he does the best commentary and impressions and it ALWAYS makes me giggle like no other. I'd be happy to do it for hours with him.
Similarly, I love driving with him. Again I know it sounds boring but we used to have to do a lot of trips that were 3+ hours long and it's just been great. Generally I think it's probably mostly about just being around each other, you know.
Idk. Walking around haha.
We both love to hike but we've never been able to go together. I also like seeing music with him, but he's a little antisocial lately and gets really tense in larger crowds (he'd consider 100 people a large crowd) so I havent asked him to go as much.