I'm not understanding people's answers for the "most practical" category. That's probably because practical isn't a very specific word, and not one I'd use for categorizing a hero. "Practical", to me, would mean that the hero in question won't get shut down by just one thing, and also that it can be included in most armies because it's inexpensive. I think that Boromir, Aragorn, So I disagree with most of the suggestions for most practical... but that's probably because I don't understand the OP's real meaning because the word is generic.
Most of these boil down to which one is the most underpriced. Pricing is everything in this game. Even if something is useful, it won't be in points matches if GW has overestimated it's power.
So who do I think is the most underpriced/broken? Currently, I've noticed that Forlong the Fat's pricing is a little wonky. Following the GW stat formula, he's got a "free" wound, which is pretty major. He's priced like a captain, yet he has more strength than even Aragorn, and I don't know many heroes under 100 points that do that. Having 150% the might of a normal captain also helps him out, considering that might is one of the main reasons people take heroes (imo the primary one). The downside is that, thematically, you have to include some... axemen of Lossarnach... to go along with him. Ugh. Well, I guess about 3 wouldn't hurt...
As for evil, I'd say Ringwraiths are the most underpriced. Good has to pay at least 3x as much for a decent spellcaster, which really keeps spellcasters off the good side's table, where ringwraiths are really cheap. Their profiles can be altered, as well, so they fit into most any army (especially considering their allying capabilities).
There are lots of overpriced heroes... in fact, I'd say that most are overpriced. I don't get what's the big deal with them... Could someone explain this to me? I have little experience, so I'd appreciate any explanation that isn't solely comprised of "stand fast".
Boromir, CotWT is at the top of my list. Someone really screwed up, there... I think that they meant to include the price of the banner of Minas Tirith in his profile, because his stats suggest that he's worth 125 points, but his actual cost is 175. The difference is the cost of the banner of Minas Tirith, which is, for some reason, not included in his profile. Someone messed up, and everyone probably thought it was intentional, and now a wonderfully themed hero is unusable.
Theoden is overpriced. Compare him to a captain of Rohan, and you'll see what I mean. He's another nice sculpt, and a nice thematic model that seems to have been made obsolete.
The king of the dead is pretty bad, too. Only one attack, yet his only redeeming feature is an "assassin" special rule? He doesn't even have any might, and his stand fast only affects his overpriced followers (who have the courage of Gandalf). I don't get it.
Anything with a "free" point of might/will is generally overpriced, imo. Don't shoot me... Let's take Aragorn for example. Judging by his stats, GW thinks that his free might is worth 80 points. Since might is supposed to be 5 points a pop, to make up for the cost of "Mighty Hero", Aragorn should be using 16 points of it in the game. A fan of Aragorn would probably say that he does use at least 16 points of might per game, but that's because it's just there... all you really need are a couple of critical heroic actions, you don't need a heroic combat every single turn. So I might pay 30 points for 2 points of might (Eowyn ftw
), but I would never pay 80 points for "unlimited" might, simply because I don't need that much. Even though the 80 point deal is cheaper on average (like buying in bulk), if I only need 2 points in a game, then the 30 point deal is better.
And don't get me started on the Baggins' and other hobbits.