Manga.
Though I've lived in America my whole life, I've grown up watching everything Japanese since my sister introduced me to Pokemon and Sailor Moon when I was two-ish. Always preferred Japanese animation and books over everything really :P
I love manga but I am American and comics are something we hold close to our heart as an American past time. I as a kid growing up knew nothing of manga when I was young so comics like Spiderman were what I fed off to give me creative inspiration. Then when I got into my teen years manga became so popular that it was unavoidable to get into,now I can't stay away from it so yes manga is what I like better but American comics always has a place in my heart
Going with US comics, no hesitation. Anyone who want to get into them out to look into the upcoming Marvel relaunch (not a terrible reboot like DC's, just a reshuffling of teams and authors).
I like comic books a tad more. They have colour on all pages, but too bad they always change authors and artists after every arc. Depending on the author, characters can have massive personality changes. It is inconsistent, but I still like it. I personally liked the X-Men and any side x-men series. A lot of characters with unique personalities.