Warriors:
Gladiator's Defense - it's foolproof in that your heroes won't cancel out of it like they would pretty much every other defensive stance.
Eviscerate - Axe warriors are going to make the best W heroes because their Deep Wound is unconditional. Do you really trust Koss to only land a Gash on a bleeding enemy or Crushing Blow on a knocked down one?
Rangers:
Barrage - unconditional mass damage, gets the nod on fire-and-forget grounds.
Broad Head Arrow - easy Daze in PvE, a very helpful skill.
Elementalists:
Elemental Attunement,
Second Wind - The only two elite energy management skills I can imagine being used to good effect by heroes. Something like Glyph of Energy would be useless (they'd blow it on a Flare), and I don't trust them with Ether Prodigy.
Blinding Surge (Nightfall) - An easy way to give yourself a Flashbot. Only requires ~5 points in Air magic to be useful.
Monk:
Blessed Light - highly reusable hex/condition removal makes this a great utility tool.
Glimmer of Light (Nightfall) - the near-instant recharge means you can make this the only "pure" heal on your monk's bar and fill the rest with utility.
(In practice, a lot of hero monks will be best off with Energy Drain on a Me secondary)
Mesmer:
Energy Drain - the best elite energy management available to them (since you can't really trust heroes to manage Mantra of Recall well).
Psychic Distraction - yet to be tested, but the idea of an infallible interrupter with 2s recharge is pretty tempting.
Ineptitude - easy high damage.
Necromancer:
Spiteful Spirit - the best area damage in PvE, it's reasonably foolproof in fire-and-forget terms. An SS necro is also more party-friendly than an MM would be.
Blood Is Power - can you honestly tell me your elementalists aren't tingling with excitement at the idea of a pet battery necro of their very own?
Ritualist:
Not a lot of great options here. I'd have to say
Wanderlust for general fun use, maybe
Spirit Channeling/
Attuned was Songkai for energy?
Ritual Lord doesn't sound like a good idea - I doubt Heroes will be able to manage their energy well enough to run spirit-spam-on-recharge.
Assassin:
Temple Strike - If you're going to run a 'sin over a warrior, you may as well give him the tools to be genuinely good at shutting down that single target he's going to go after.
Flashing Blades - on the other hand, maybe it's a better idea just to help him stay alive!
Dervish:
Reaper's Sweep/
Wounding Strike - may as well maximise the use of those AoE Deep Wounds.
Sandy Grip - or AoE Blind, I hear that's also pretty nice.
Any Avatar - for coolness value.
Paragon:
"The Power is Yours!" - who cares if he gimps himself, if he's feeding the rest of the party?
Cautery Signet - handy, especially since your hero monks will actually be able to bring condition removal to strip the burning!