Depends on what you plan to use it for, but Aron is common enough that I have two 2700 Aggrons just from boosted wild catches.
Iron Tail I have paired with Heavy Slam for reliable Steel DPS and bulk against certain bosses (Jynx anchor, Granbull and Piloswine come to mind, as does Aerodactyl).
Dragon Tail I have paired with Stone Edge as a 6th slot for Dragon Raids, but it was more effective on Ray than Latios.
Alakazam truly depends on whether you dodge or not. If you don't, Confusion will get off more damage. If you do, PC will give you generous time to do so, while having decent dps and energy gain