Only records and almost always completely through unless listening time is over or there is a song I can't stand - luckily very few out of about 350 records. Double albums are the only potential exception. If I have had enough for a while, I will go through the other rotations and start back with the second record for that rotation. I try to listen to all equally to the degree I can - it's OCD trying not to waste any of them. I am not a collector.
Interestingly enough, once in a while I will hear a song I really like while driving listening to Sirius XM and I'll buy the record if it is available, just for the one song. Only once was I not happy with the entire record, but I liked the one song so much it's OK. Example - Paul Simon - One Trick Pony is a great song, but I only listen to the side that song is on - I think the other side stinks - no offense Paul. But One Trick Pony is a great song - not a great album. I think the song is about Art Garfunkel even though I think it is also a movie soundtrack.