[G]
A lot of things now get Geomancy; notable users include Gengar, Goodra, Galvantula, Gastrodon, Glaceon, Greninja, and Gothitelle (hint hint Shadow Tag hint hint). Gorebyss could Baton Pass a Geomancy boost instead of a Shell Smash boost if it wants to give something massive special bulk as well as power and speed.
continued...
[H]
Hydreigon, Heliolisk and Houndoom get Hurricane... 'nuff said. Oh, and Heatran gets Heal Order. Hippowdon could become a cleric with Hell Bell in combination with Slack Off / Heal Order and its natural bulk. Honchkrow can now rip through opponents with Hi Jump Kick.
[I.]
Infernape can use various Ice moves including Ice Beam, Ice Shard, Ice Punch and Icicle Crash on any of its sets to rip Dragons and Gliscor to shreds.
[J]
Jolteon can use Judgement with either a Flame or Icicle Plate for massively powerful coverage; Jellicent, Jynx (who also gets a reliable Sleep move) and Jirachi can use this too but Jolteon does this best. Jirachi's physical sets could use Jump Kick for those blasted Steel and Dark types.
[K]
Kingdra, Kabutops, Kyurem-B and Klinklang all appreciate Knock Off on their physical sweeping sets; Klefki could use it to become even more annoying than the bastard thing already is.
[L]
Latias stalls with Leech Seed and both Ion twins can finally use Lava Plume to KO Steel types; Lilligant also appreciates Lava Plume for some actually decent coverage on its Quiver Dance sets. Liepard gets a priority Leech Seed, Lovely Kiss and Light Screen to royally p*ss you off. Luxray can use Leaf Blade to crush the Water/Ground Pokemon, while Lucario / Mega Lucario can use it to rip apart the bulky Waters who can usually tank its attacks.
[M]
Machamp finally gets Mach Punch and both it and Mamoswine have nabbed Meteor Mash to rip apart Fairy types (and maybe get an attack boost while they're at it). (Mega) Medicham can use Mach Punch too, and Metagross gets Megahorn along with fairly reliable recovery in Moonlight / Morning Sun. Mismagius can blow away Darks with Moonblast, and Moltres can have fun with Muddy Water for opposing Fire types. Malamar might like one of the physical moves on its sets for specific threats (like Mach Punch to take down weakened pokemon afetr a Superpower boost), although it isn't totally necessary.
[N]
Ninjask can now Baton Pass Nasty Plot boosts if it so desires, and Noivern can sweep or even wallbreak with Nasty Plot in its repertoire. Nidoking and Nidoqueen might enjoy Night Daze on their Sheer Force sets.
[O]
Omastar can enjoy having Oblivion Wing on its Shell Smash sets to break down Grass types; and has advantages over Ice Beam (Oblivion Wing hits Mega Venusaur and also heals Omastar). It also rips most Fighting and Bug types to shreds.
[P]
Porygon-Z / Porygon2 can use Psystrike to annihilate Special walls like Blissey, though the lack of STAB will probably mean using it in conjunction with Nasty Plot to make full use of it.
[R]
Raikou becomes arguably the best offensive Rapid Spinner ever, while Roserade, Reuniclus and Rhydon / Ryperior can use it in conjunction with their bulk and / or access to other entry hazards to become great utility Pokemon. A lot of bulky Pokemon such as the aforementioned Rhyperior, the Regi's and the Rotom formes all get Recover / Roost too, making them very difficult to take out in the hands of a smart player.
[S.]
Sableye gets Prankster Spore (among other things) because it's just not annoying enough to deal with, and can also use Spiky Shield over Protect if you fancy. A lot of physical attackers such as Scolipede, Samurott, Salamence, Scrafty, Sharpedo, Staraptor and Swampert get access to the amazing Sacred Fire. Basically anything you want could use Sticky Web or Stealth Rock, in particular Sableye, who is immune to Rapid Spin and gets priority on these moves. Sceptile appreciates Sludge Wave on its special sweeping sets and can also use Spacial Rend if it wants. Scarafty and Sharpedo get STAB Sucker Punch, and Skarmory loves screwing opposing walls over with a Super Fang + Toxic combination. Anything listed here (and others) can now use Switcheroo too, if you are one of those players.
Oh, and Slaking gets Skill Swap. Have fun.
[T]
Thundurus, Tornadus (and their Therian forms), Togekiss and Typhlosion can use Tail Glow and rip walls to shreds; Typhlosion also appreciates Thunderbolt for the annoying Water types it frequently faces. Talonflame gets a lightning-fast Taunt, and you could pick from a decent selection of Toxic Spikes users now.
[U.]
Ursaring gets a Guts-boosted U-Turn for powerful pivoting; there's not much else here though.
[V]
(Mega) Venusaur likes having Volt Switch or Volt Tackle for incoming Talonflames, and physical Virizion loves V-Create. Volcarona, Vivillon and Venomoth all get access to Volt Switch should you want to test the waters before using Quiver Dance or Sleep Powder. Chlorophyll Venusaur and Victreebel with Growth love abusing sun-boosted V-Creates.
[W]
Weavile can use Water Shuriken or Waterfall for Fire types or pack Wild Charge for Gyarados, and Wobbuffet becomes hella annoying with Will-O-Wisp.
[Y]
Yveltal is already good at forcing plays with its typing, access to moves Sucker Punch and Taunt and its general bulk (augmented by Roost); Yawn would simply make it even better at this, especially in conjunction with entry hazrads... could be a top-notch annoyer in Ubers.
Phew, that's a lot of awesome stuff.
