As my bullet journal I'm using a Midori MD notebook (A5, one page a day) with a pretty calendar sheet wrapped around for looks and the "official" plastic cover for protection. It's nice, but not for those who dislike ghosting (I don't care though). For the next year I'm thinking of going back to leuchtturm, mostly because I will need a more calendar-like format and less space, so it doesn't make sense to lug around nearly 400 pages. And leuchtturm is pretty solid.

As my longform journal I'm currently using a nuuna A5+ notebook barely fitting into my Galen leather notebook cover. Some inks bleed through but I really like the 3mm dotted lineature and the outer design. I used to use the galen A5 tomoe river notebooks (blank) with this cover (same purpose), but I only have one left with the original TR and felt like delaying it's use for another year. TR is great for showing ink properties, but feels a little bit flimsy.

For work I have a B5 stalogy notebook without cover, great for dated short notes. Also TR paper.

For various personal projects (like PNP characters and notes) I tend to use Clairefontaine paper bag notebooks, as they are good, look nice but are comparatively cheap.

For random notes I use the dotted A5 spiral pad by Brunnen. Works great for notes, even shows some sheen, bleeds through for wet pens, though. Since I'm going back to university next month, I'll probably invest in an A4 one again.