Reception playlist??

My FH and I went back in forth on songs until we reached about 3 hours worth of music.

We picked all the songs we wanted for the special things (ceremony songs, first dance, etc.) and a bunch of must play songs. We also gave him some genres like classic rock, 90's pop and modern. He asked if we had any specific modern songs as he doesn't really listen to any and isn't sure what we may like so we looked some up. We probably gave him a good hour or 2 worth and he has a bunch more he will play based on what we like. If you're particular on the kind of music then I'd give your DJ as many songs as possible. Otherwise maybe talk to them and ask what they prefer. Perhaps they can give you an idea of the music they've played at other weddings so you can get an idea of what to expect from them.

We’re picking songs for the special events like cake cutting and first dance, telling our DJ what genres we like, and letting him take care of the rest.

This depends on how important specific music it is for you. DJ can definitely play music all night on their own, if you just give them your preferred music genre & songs for special events, like first dance, cake cutting etc.
But if music is really important to you, then you can put a list of must play songs & give it to your DJ.
We have a long list of songs for cocktail hour, dinner & dancing part. I love music & have ton of it, so for me it was very easy to put down a list of what I want to hear at our wedding. We also asked guests to write their 2 favorite dance songs when they RSVP & then we included some of these on our playlist as well (only the good ones that we like too lol).

I asked guests for song requests and that was enough for a portion of the reception and the other times my DJ had his own playlist I sifted through

We opened up a bunch of Spotify playlists and just started jumping around to stuff we liked.

Then we curated as to what was dinner, or ceremony, or dancing.

Honestly, FH did most of the work, I'm not much of a music person. I love to dance, but darned if I know anything post early 2000s... and I don't really listen to music unless I'm in a car or in a place that plays background music.

Same as above. We gave specific “special” songs and a few “must play”s but that’s all. Our DJ is taking care of it. He knows what music we like, and we trust him to make the evening enjoyable.

We came up with some specific songs that we definitely want played. Then we had another meeting with him and went over the style of music and when we want it played and asked him to fill in the rest. We will have one more meeting with him a few weeks before the wedding to go over what he's chosen as the playlist and make any adjustments at that time.

We're going to ask people to put song requests on the back of their RSVP cards so that way they have at least one song to look forward to.

Our DJ gave us a form to fill out with songs for the big moments - walking down the aisle, first dance, etc - and then opened it up for us to list anything we definitely did or didn't want played, as well as genre suggestions. He said not to make a playlist because he'd end up reading the room to choose what to play anyways, and completely trust him to do that well. We'll probably try to give him a decent list of things we'd like to hear and just let him run with it.

We have a portal with our DJ that has "must plays", "do not play", and all of our specialty songs (first dance, cake cutting, etc.).

Thanks for the suggestions everyone! Our DJ sent us over some playlists of other weddings he has done last night. I've been going through those today and putting down our must plays and we're going to let him just fill in the gaps for us. Not sure I could come up with 3 hours worth of music to play! haha