Cast times
Longest cast time is 20s, for the base raid 'Deploy Pylon' power. But base raids aren't available.
After that is 17s cast time, for things like Pocket D VIP Pass, Mission Teleport, Base Teleporter, etc.
The Particle Cannon from the Abandoned Sewers trial has a 15.67s cast time.
Black Market/WW teleporters have a 15s cast time.
Self Destruct has a 10s cast time. (Really?!?!)
Finally, the longest in-set cast time is Time Bomb, in Traps, at 9s.
Edit: It looks like the slowest attack, for players (which isn't a nuke or snipe/AS) is Propel, from Gravity Control, at 3.5s
Edit2: For the opposite question (fastest, barring auto powers), it looks like Hibernate is the fastest casting player power, at 0.07s, with Gambler's Cut as the fastest attack (0.67s)
http://www.fimfiction.net/story/36641/My-Little-Exalt
Oh, there are nukes which are slower than Propel, but I figured you'd want to exclude them.
http://www.fimfiction.net/story/36641/My-Little-Exalt
Propel may be the slowest attack in the game but 0h-so-worth-it.
Smacking a Freakshow Tank in the noggin with a pool table just
never
gets
old.
Ignoring snipes and Assassin Strike (which is essentially a melee snipe) what attacks in the game have the longest animation times?
-----
Mission Architect Handyman