Fighting decks are very strong indeed. Thanks to all their great support released in Furious Fists and recent sets. I don't mind that, but what I think is kinda unfair about fighting types is that they have a huge variety of weaknesses. Here are some examples that are used competitively:
Psychic: Lucario EX/Machamp EX/Gallade BRT/Mienshao FFI
Lightning: Hawlucha
Grass: (Primal) Groudon EX/Terrakion (EX)
Water: Groudon EX DEX/Landorus EX/Landorus (FFI)/ Donphan(PLS)
So how do you counter all these? I can't think of anything specific :/
The short answer is: you don't.
The Fighting-Type is a strong Type, perhaps the best in terms of Type support. I don't find having a variety of Weaknesses to be unfair or unbalanced. I find the Weakness mechanic with its damage doubling to be unfair and unbalanced, but when it comes to Weakness itself, my experience is that the game does better when a Type has diverse forms of Weakness built into it. If you don't you tend to suffer the opposite problem; a vast amount of decks built around mostly (or only) one Type and it gets wrecked by a single solid attacker exploiting Weakness. So overall, you probably just need to learn how to play what you are already running against these decks... or move onto a different deck if any and all Fighting-Types are wrecking you.
Or in short... what
@bbninjas said.
Looking at your list of problem Fighting-Types (some of which are only issues when you are totally unprepared or are starting out and just won't have very good decks to begin with), there are some you shouldn't worry about. Most obvious is
Hawlucha (FFI) because it has 70 HP. If your deck can't deal 70 damage easily enough to keep up with
Hawlucha (FFI), something is probably off with your deck. Exploiting Weakness will lead to pointless overkill for attacks that do 40+ damage, while attacks that do 30 or less still whiff. ^^'
Mewtwo-EX (NEX) has long been the go-to answer for Psychic Weakness.
Mewtwo-EX works well in many decks; have
Double Colorless Energy or a compatible form of Energy acceleration and you can wreck anything Psychic Weak. Exploiting Grass or Water Weakness is much more difficult, at least while keeping up a general strategy. You've got to go with an Evolution for good Grass-Type attackers, either
Leafeon [Plasma] or
Vespiquen (
XY: Ancient Origins 10/98). For Water, don't understimate even an off-Type
Keldeo-EX.
Just getting slaughtered by Fighting-Type decks and need to explicitly build a deck around taking out Fighting-Types? Consider Night March or the aforementioned
Vespiquen. Both should hit hard enough that Weakness won't be needed, but do hit some of what you list. If you are playing Expanded, you can combine
Vespiquen with
Flareon,
Jolteon and
Vaporeon (all from AOR) so that it can hit Grass, Fire, Lightning and Water Weakness. Throw in either
Mewtwo-EX or
Mew-EX and you've got Psychic covered as well.