>>30319018>Special Defense, Defense, HPAlways max them if possible. Very few exceptions exist, and they are almost always due to a gimmick build.
>SpeedNot quite as must-have as the above, but you'll want max Speed more often than you don't. Again, usually gimmick builds are going to not care about their Speed IV at all.
>Attack, Special AttackDepends. If you're a Special Attacker, you want your Special Attack IV to be high and your Attack IV to be as close to 0 as possible. If you're a Physical attacker, you want your Attack as high as possible. If you're a mixed attacker, then god help your soul because you probably want all 6 perfect IVs.
Really, though, IVs are completely inferior in stat gain compared to Natures. I don't remember the exact numbers, but IVs give significantly less stat gains at Lv 50 than Natures and EVs do. If you have to pick between a mon with a bum Nature but perfect IVs and a mon with meh IVs but a perfect Nature, go with the latter every time.
