Which series had the better 'war arc', Magi or One Piece? I personally prefer Marineford more (only by a little bit, with the death of Ace tipping the scale ever so slightly), but what do you guys think?

Marineford. Magi is a great series, though.

Marineford, but I can’t wait for magi to return.

Magi ended more than half a year ago, so I don't know what you're talking talking about.

Marineford because Whitebeard kicking Akainu's ass was one of the most satisfying things I have seen.

I can't argue with you there, that was an absolutely amazing moment.

Marineford for me. It was so loaded with awesome moments like Luffy standing before the 3 Admirals, Luffy using conqueror's haki and impressing all the strongest guys on the battlefield , Whitebeard showing his abilities and beating up Akainu, Mihawk realizing what's Luffy's most dangerous power , Garp wanting to kill Akainu ... the list goes on, just too many great moments.

Post 7 reminds me of a guy who said Whitebeard fans need to stop wanking Whitebeard because Akainu "clearly slaughtered Whitebeard" and that Post TS Akainu would have more hype than Whitebeard did.

I really liked Magnostadt arc, but Marineford arc is certainly more fun to watch.

Yeah, it had a lot more individual fights happening alongside the main battle. In Magnostadt, it was essentially just everyone against the Medium.