I'd put Trick Arrow/Radiation Emission/Dark Miasma at the top probably.
Poison isn't great at everything, it needs some dev attention - going by raw numbers it's great but in practice it's difficult to maximize due to several things: the time it takes to dump your payload, the way the AOE works is weird because the original design meant for you to spam different targets with them so that the weaker debuffs on the outside of the target would get layered with the primary and secondary values - oh and also you are expected to get within melee range for Venomous even though the set doesn't let you heal yourself or give yourself any buffs whatsoever to survive. The heal takes really long to affect your target depending on the situation, etc.
Cold is a mix, it could use just a couple tweaks but it's good.
Traps is really great on a mastermind specifically, and it's tier 9 could be reworked more if you ask me. Better set than some realize as a whole though, specifically Acid Mortar, Force Field Generator. Triage should be reworked too.