I'll be in melee a bunch anyway as I want to leverage the pbaoe hold in NA.
My take is
/water would be fun because of all the kdown the set has. lots of potential smash type fun there.
/Psy has all sorts of control in it. Would be very safe and it's fun to play controller with other sets.
Plus with fast snipe, it has an incredible single target damage potential (something like 240 DPS... On a Defender?!?!).
/Elec has huge end drain potential which would be very effective in crowds. Imagine stealthing into a crowd/wait for hold to take effect/drain/damage. Plus it has a snipe to fast leverage.
/BR adds to a weak point in NA... it's -regen. It also has a very good single target DPS, but I can't calculate it at all since it relies on disintegrate.
I also have a theory that the disintegrate spread capacity can be leveraged into a decent aoe by respreading. The snipe would help that. Once again I don't really know though.