C – core set
M – Shadows of Mirkwood cycle
M1 – Hunt for Gollum
M2 – Conflict at the Carrock
M3 – Journey to Rhosgobel
M4 – Hills of Emyn Muil
M5 – Dead Marshes
M6 – Return to Mirkwood
K – Khazad-dûm deluxe
D – Dwarrodelf cycle
D1 – Redhorn Gate
D2 – Road to Rivendell
D3 – Watcher in the Water
D4 – Long Dark
D5 – Foundations of Stone
D6 – Shadow and Flame
H – The Hobbit saga
H1 – Over Hill and Under Hill
H2 – On the Doorstep
N – Heirs of Númenor deluxe
S – Against the Shadow cycle
S1 – Steward’s Fear
S2 – Drúadan Forest
S3 – Encounter at Amon Dîn
S4 – Assault on Osgiliath
S5 – Blood of Gondor
S6 – Morgul Vale
Beorn (H1) is the beast (the bear) of action advantage. The ability not to exhaust to defend is just priceless in so many situations, especially when combined with 10 hit points and sentinel. The 1 point of defence is of course a trouble but almost every scenario contains a number of weaker enemies. And despite the problem of having few combos for Beorn (due to his immunity), we can wait in hope that one day there will be a card that lower's enemy attack strength.
The tactics version of Boromir (M5) is as heroic as one can imagine. There is just so much Boromir can do with his seemingly unlimited action pool. You just need to find ways not to run out of threat, and also to make the actions count - by boosting Boromir's attributes.
Elladan (D2) can hardly be competent with the above as his action advantage is only limited to multiple attacks. The limitation goes much further as you need to have Elrohir to make any sense out of Elladan's attack strength.
Trollshaw Scout (D5) is an ally equivalent to Elladan, with the exception that you pay with cards instead of money, and if you don't pay, say goodbye to the scout. Not great, especially as the cards are very precious in the Tactics sphere.
And it goes worse with Watcher of the Bruinen (D3) whose action advantage lies in expensive multiple defence of 2 strength and 2 hit points; allies rarely go any worse than that.
Behind Strong Walls (N) is not groundbreaking either but for Beregond, it works very well.
Aragorn (C) was a master of action advantage back in the dark ages of the core set. The ability is still good since having a hero ready upon questing is very useful.
As opposed to Aragorn's ability, it doesn't cost thing to ready Prince Imrahil (M3), that is if you don't count casualty. But really, there are so many allies now that leave play without being destroyed, that it gets ever easier to take advantage of Imrahil's action advantage. The problem is it only works once per round.
Yeah, Outlands have got Forlong (S2) who readies eight times a round if you have the right collection of his colleagues. But it hardly matters once you do. Another waste of a card slot, when it comes to imaginative card design.
The fact of the game is that the opening rounds are often essential in the outcome of the quest, thus almost any card with the cost of 0 should be at least considered. Cram (H1) is no exception.
Path of Need (D5) may look awesome but it is complicated to get a proper advantage out of its cost of 4. The fact you may only have a single copy in a deck makes it also hard to rely on it even if you build around the card.
Ever Vigilant (C) was another core set favourite, especially as a good companion for Gandalf or Faramir of the same set. It gets harder to justify its place in a deck now with the card pool ever growing.
And one of the reasons is Strength of Arms (S2), a perfect card for a mono-Leadership deck. The most surprising experience is that even such a blast of a card - which readies all allies in the game for mere two Leadership resources - may still often sit in your hand for the entire game.
Lure of Moria (D2) is similar to the above, an obvious hit in the Dwarven decks, no need for full-Leadership line-up; all Dwarven line-up is preferred, though.
Like Path of Need, Grim Resolve (C) is another example of a card with great potential that may be just too expensive to have in a deck (especially more than once).
Éomund (M2) might find the spotlight in the upcoming cycle when more Rohan characters are expected. As it is, there is little use for him but that can quickly change.
Ever My Heart Rises (D4) is another of those situational cards, only useful in some quests, in a very few actually.
There are a few characters who can use Spare Hood and Cloak (H1) quite efficiently, but overall it falls into the very situational card category.
Light of Valinor (D5), on the other hand, should be a no-brainer whenever you have Glorfindel on your side. And if you don't, but do have a different Elf who tends to go on quests, then you might included as well.
And then there is Steed of the Mark (S6), a card that pales in comparison to the above or below. But one can still hope its importance will grow if there's some ultimate mount synergy in the work of the future.
As there is a little reason why not include multiple copies of Unexpected Courage (C) in a Spirit oriented decks, especially those having more than a single Spirit hero, it might have been the reason why people bought multiple core sets. Well done ffg.
Quite like Cram, in an amusing (anti)thematic way, Miruvor (D6) can contribute massively for the one resource which you might very well get back - or even transfer to a sphere that needs it more. The latter of which may be quite rare but when true, Miruvor really shines in its versatility.
Renewed Friendship (D1) is also quite versatile but only when you know other players will be playing attachments on your heroes.
Light the Beacons (N) is a great defensive card, and provides a huge action advantage, for the Spirit sphere, just as long as you can afford it. Mono-sphere stuff, surely, though there are other short cuts.
We Do Not Sleep (M5), on the other hand, is just poor for what it does; highly situational.
Looking up this category, one can clearly see Lore is the least able of the four spheres. There is no action advantage safe for Dwarves and Hobbits. Erebor Record Keeper (K) works nicely for the former.
And Fast Hitch (M5) for the latter. This is what Light of Valinor is for Elves, only not unique. Just as it is right now, few Hobbit heroes can really take a great advantage of it, especially the two within the sphere.
As noted above, the better the stats, the more useful action advantage gets. And the stats hardly go better than the quadruple 4 that the Grey Wizard possesses. The Hobbit version of Gandalf (H1) does not exhaust to commit to the quest, which is fits perfectly with decks that can afford the threat raise.