Eri is still the best, but Yakumo is wonderful.
And then I watched the first School Rumble San Gakki OVA. This is where my diligent spoiler-avoidance policy backfired on me. Had I known anything at all about the episode before watching it, I would have at least learned that it begins with a five-minute clip show that spoils basically everything that happened after the second season to the end of the manga. Ah, Hell. There goes my waiting-for-Del-Rey plans. So yeah, I finished reading the School Rumble manga the other way.
The post-second-anime-season events of the manga surprised me a little in that they largely took the focus away from Yakumo and put it back on Eri. Now, Eri is the best, but I think it was a mistake to downplay the Yakumo/Harima friendship after developing it so much.
Even though Eri is the best, I think we all know there will never be a full-fledged Harima + Eri romance. The Yakumo + Harima stories, on the other hand, have the advantage of being about friendship instead of romance, so they have the freedom to advance and explore avenues unavailable to the other pairings/factions.
If you've followed the story from the beginning, you'll remember that the Yakumo and Harima friendship is a somewhat unlikely one that sort of developed almost by chance, but has gotten steadily stronger over time.
Harima holds Yakumo in the highest regard. Unfortunately, Ni Gakki missed a golden opportunity to explore this friendship further during its later episodes. It did a pretty good job at the beginning and the middle of the season, but their interactions grew inconsistent towards the end. At least we got Jedi Mind Shit and face-drawing moments to offset the inconsistencies. I fault the rather half-hearted attempts to craft Harima + Tenma stories which are pretty much a waste of time.
Given that the vagaries of love predominate as the primary School Rumble staple, developing a diametric theme via Harima and Yakumo's mutual reliance and trust in each other invites us to remain hopeful that, despite the uncertainties of love and life, come what may, we shall at least be left with One Good Thing. Perhaps that is enough.
P.S. The School Rumble manga should have ended with chapter 281, alas. I sure hope School Rumble Z is good. From the looks of it, I think it's going to be a bunch of alternate-universe stories with the same characters. Tenma seems a little dumber than usual, though.