What ATMAS to use

[Randwolf]

Most of the atmas you need is achieved by camping Jeuno, they are plenty of shouts. Generally Razed Ruin, voracious violet, Minkin Montrosity (are widely considered the big 3), these are mainly refresh and damage atmas. Some others that are good in a pinch or for tanking NM's and zone bosses which I'm the backup tank to our NIN, would be Gnarled Horn, Cloak and Dagger, Apocalypse, even some good nuking atma if you choose, there are several others that are good as well. Here is a link that lists the atmas on wiki: http://wiki.ffxiclopedia.org/wiki/Atma definitely take some time to read up on it.

Yeah, it's very situational. The first 3 mentioned though will serve you most of the time. It gets much more specific when you start fighting NM's. However, some can be rather difficult to get if you don't have a good group trying to get them.

[Scuro]

MM VV RR for DD
atma of the ultimate, MM, and atma of the impregnable tower for Magic casting I would say