Web Grenade - Useful in PvP, and to bring down flying foes in PvE
Triage Beacon - Only take if you have nothing good to get
Force Field Generator- Very nice power, take it, slot it, love it.
Poison trap - I hear it's great, not seen it used much.
Seeker drones - They can be useful, don't have too good AI though.
Detonator - Haven't seen this one in action.
Web grenade. Awesome in PvP, good in PvE with Caltrops.
Triage - Good if you've got a prolonged battle.
FFG - Nice 
The rest I haven't got yet.
Caltrops over the Acid Mortar with a Triage next to it is rather cool though
Web Grenade - Essential. Take it (not that you've got a choice 
), slot it, spam it, love it. Keep the enemy at range, and let your bots use all their ranged attacks on that webbed in place target.
Triage Beacon - Very Useful, get it slotted with 3 recharge and 3 Heals as soon as you can spare the slots..
Force Field Generator - Take it as soon as possible, and use it all the time. Mez resist and +def for a MM? Oh yes.
Poison trap - Take it and use it, whenever you can. It's an AoE Hold. That should say it all.
Seeker drones - No real need, since your PB's will be dumping seekers constantly when fully upgraded.
Detonator - An absolute pile of steaming wossname. Avoid.
Use Trip Mine instead of Detonator if you feel a need for big bangs.
Acid mortar is useful too.
I never took Caltrops, so I can't really comment on it.
I'd have replied earlier, but for whatever reason, the boards weren't letting me...
:edit: Typos.
Warning:
The above post may contain Cynicism, sarcasm and/or pessimism. If you object to the quantities contained, then tough.
Caltrops is seriously one of the best powers in the whole traps set. Just slot it for Slow not Damage
Web Grenade - excellent power in pve and pvp - especially useful in pve for those missions where you have to stop the av from escaping. useful in pvp if you can keep it stacked to stop people escaping.
Triage Beacon - excellent for henchmen that stay in one place - ie mercs/robots - less useful for zombies/ninjas
Force Field Generator - utterly brilliant power gives mez protection as a summon. if a member of the team gets held, bring the generator to him and he is unheld - only bad thing is sometimes he doesnt follow you as closely as you would like and if you forget to give him grant invisiblity he ruins your stealth
Poison trap - great unresistable temporary hold - sort of a slow in a way because it makes the bad guys vomit for a few seconds.... ah sod it it's great just because it makes them vomit.
Seeker drones - perfect for taking the alpha strike from a big mob - also reduces accuracy which is one of the best things you can do to an enemy really. Will stack with the drones from your pro bots to floor the enemies accuracy. the fact that your bots have seeker drones too makes it more useful to have a power that you can stack with it so i completely disagree with the poster above but I'm sure he's a nice person really he's just WRONG :P
Detonator - very situational - bit of a novelty power but I like it anyway because its just FUN but if I was a true power gamer I would not take it because it reduces your effective dps by 0.45 per cent etc etc god how boring is that.... its FUN
Thnx for your opinions guys, I am gonna try and get;
Web Grenade: Have no choice, good aganist goldbrickers and longbow.
Triage Beacon: A lifesaver in some cases, excellent with robots.
Force Field Generator: Just love it.
Poison Trap: Not really sure on this one, never seen it in action.
Seeker Drones: Excellent bombs and cannon fodder.
Detonator: Cool with bots.
PS: Sorry about the typo on the thread title.
I was planning about which traps I would use for my robot MM and I wanted to ask what do you think of the following powers:
Web Grenade
Triage Beacon
Force Field Generator
Poison trap
Seeker drones
Detonator
Use it as a template and put your comment next to the power.