(I posted this last night, where the fuck did it go)
Obligatory Aiki rec. Tate no Yuusha No Nariagari a good second so far. I'd also second the other anon's Sunabozu(Desert Punk) recommendation. If you don't mind the "he's an asshole but secretely nice" thing, YuYuHakusho, Ocha Nigosu, and Beelzebub match that pretty well. Hell, most any manga with a delinquent MC does. Koe no Katachi's MC was a douche, but the manga is about his reformation.
Other than that, Fukushuu Kyoushitsu, Teppu, Ningen Katsuki Tatsuo, and Oyasumi PunPun have some pretty irredeemable MCs. Also Ookami no Kuchi if you want the jerk of an antagonist to be nearly the only focus of the manga.