Simply the best.
And it has been preserved for me through Watterson's absolute refusal to sell the series out. The guy turned away countless dollars simply to uphold the integrity of his characters and his comic strip. Had the series blown up, been on cereal boxes, cartoon shows, bad Cgi cartoon movies voiced by Zach Efron, mugs, teeshirt a, etc.. I don't think it would hold as special a place for me in my heart. To this day I don't think there's really anything else that evokes the same kinds of feelings from me as Calvin & Hobbes does