I just started watching anime in the last 6 months or so, before that I had mostly only seen Ghibli stuff and like DBZ on Toonami when I was 12. Since I started, though, I've been making pretty good progress through shows. Here's my top 10 of what I've watched since I started this project:
Bocchi The Rock!
Dungeon Meshi
Sousou no Frieren
MakeIne: Too Many Losing Heroines!
Dandadan
The 100 Girlfriends Who Really Really Really Really REALLY Love You
K-On!
The Quintessential Quintuplets
Chainsaw Man
Gushing over Magical Girls 👀
I'm in the middle of Blue Box and Roshidere right now and they're both pretty good, though I don't think either will supplant anything in this list. I did not expect to like rom-com and slice-of-life stuff as much as I clearly do.
Well my only real exposure to harem MCs are these two, lol. I liked QQ a lot, it's a little slow at first but it's very charming. Fuu-kun in QQ is a good guy, he's not a saint like Rentaro but the show also isn't batshit insane like 100 Girlfriends, so he's more of a real person. You always like him though, at least I did, and you believe he cares about all of them. At the very least it's a fun light watch.
I haven't watched the show, but I read the QQ manga and liked it. I think the MC is definitely on the better side of the harem protagonist spectrum.
It's hard to talk about QQ without also bringing up Bokuben. I think that I liked the MC better in QQ, but I liked the (manga) ending and the girls better in Bokuben. Bokuben in particular does an interesting thing with its ending (only in manga, I don't think the anime finished the story) that I enjoyed a lot (but if I talk any more about it will definitely spoil).