Based on popularity Julian who I honestly could care less about so I let him, based on who I actually liked Kitty and Agent S who I also didn't take in because I wanted a balanced gender ratio.
I've seen some fairly popular villagers in my campsite before, but none that I cared about. But in my last town I found Bam in my campsite and invited him on impulse, and he turned out to be my favorite villager.
merenge, diana, lucky, apple, cookie, ruby
i got cookie but she left, i traded merengue, i didnt have room for diana lucky ruby or apple,
im still mad about ruby ugh
The best I got was Merry, I got her to move into my town, I've also had Julian and Merengue in my tent, but I don't like horses and rhinos So I never got them to move in
I've had run ins with popular villagers I didn't want/didn't have space for in my campsite. xD Off the top of my head I got: Zucker, Tia, Beau (technically I wanted him but I didn't have space :c), Whitney, Coco... I also got Julian and I moved him in the moment I saw him cuz unicorn. Pekoe and Rudy also moved in via campsite.
The best ones (for me) so far were my dreamies: O'Hare (but didn't have space), and Diana. I got Diana to move in via campsite twice (once in my old town, once in this new town). Both were also luck because I didn't reset to get her there, she just... camped. She loves me.