Wharf is arguably the best card in the game which you cannot use to give a curse to your opponent. It's great for big money. It's great for engines. It's not great in rushes, but then, it's pretty good at beating them.
Hunting Party is pretty clearly the second-best non-attack $5 (if we call IGG an attack here anyway, which is not technically true - and these might be better than IGG anyway). And it's entirely outclassed by wharf, pretty much all around.
Now, why is wharf so powerful? Basically, it's a Council Room that's split over two turns, with an extra buy, and most importantly, which doesn't lab your opponent. If you play one every turn, it's EXACTLY like CR minus the drawback (and with an extra buy). And Council Room is already a decent card, even with the drawback. Now, you do potentially need more wharves than you would council rooms to pull it off. But in practice, this isn't much of an issue most of the time, - you can actually get way more wharves than CRs without collision being a huge issue, thanks to the duration-ness - and giving your opponent free labs is much more important. Breaking down wharf itself, we see that it's moat with a buy right now, which isn't so special but not totally terrible, but essentially a worker's village+smithy combo guaranteed with each other next turn. And wharf has all kinds of other comparative advantages to council room as well. If there are actions you want to have played before your last terminal, wharf is a better way to do it, because you get significant amount of that draw at the beginning of your turn. This is a strength for engines, mostly, but also good in big money.
Money
If you believe the simulators - and for big money matchups, they're not perfect, but you largely should - wharf is the 5th-best single card for big money, after (go figure) Young Witch, Witch, Mountebank, Sea Hag. Yes, it beats familiar. Pretty handily actually. And the thing is, with most of the cursers, 1 curser into wharf is going to be very good on such boards anyway.
Now, how do you want to play Wharf for money? Well, there are actually several viable ways, depending a bit on what your opponent does. But in general (and say for a mirror), you want to get a couple wharves before gold, pretty much no matter what, and then get a good bit of money, with a third and maybe fourth wharf, before turning for green. In fact, it almost plays a little like an engine, because whereas with something like Smithy/BM, you want to green pretty fast - only a couple silvers and a gold is enough - with wharf, it's even a little stronger, typically, to build up a little extra more buying power before turning green. This also lets you take advantage of all those extra buys you probably have.
What works with wharf in money? Well, the first, obvious thing are your special treasures. Wharf and fool's gold is silly strong. Wharf gives you the two things that FG wants - +buys and big handsizes. Similarly, bank and wharf love each other. To a lesser extent, venture and cache can be nice, if you have lots and lots of wharves already and hit $5, and I guess Royal Seal and... Stash, which is more or less silver for you in these decks. It also works with good utility BM cards, like JoaT, though remember that wharf is the star here - doublejack with a little wharf support is not so good as wharf with jack support.
How good is Wharf-Big money? It's stronger than other money strategies, first off. It's also stronger than most simple combos. Chancellor/Stash, Treasure Map/Warehouse, Tactician/Vault, fuhgeddaboudit. Hunting Party + Terminal Silver? You need something like baron or monument to make it worth it. Embassy/Tunnel? Not unless you stop the wharf player from buying tunnels to pad his score. Native Village/Bridge... maybe. It's hard to tell. But probably Wharf dude can get a lead and then you have to be VERY careful about piles. Golden Deck... okay, you got me. Usually.
Engines
Like most draw cards, building an engine is not going to just materialize out of sticking in a village. Wharf/Money beats Village/Wharf, typically unless that village produces money for you. Bazaar and festival probably give you some modest gains over straight money, even without other help, and fishing village... well, fishing village is fishing village.
Bigger exceptions to this rule, though, come in the form of the $2 villages. Native village and hamlet are nice things to pick up with a spare buy here and there, and they're cheap enough that you can cobble together an engine pretty nicely with all your spare buys. Crossroads is the real star, though, giving three actions and, moreover, taking advantage of your bigger handsizes itself, as the green you'll pick up can really really help. Also, I'd be remiss to not mention border village. Very very often, you want to buy wharf on $6 anyway. The BV is a big bonus.
Engine-wise also, what the card gives you is zillions more cards. Other card draw qua card draw isn't necessarily bad, but you usually want wharf instead. Now, if it holds a good attack, a la margrave or ghost ship, you might make an exception for a copy or two. But the bread-and-butter of the engine should almost always be wharf, because it's just more powerful.
It's also important to note that wharf engines build a good bit differently than those based around other draw cards. Basically, you need fewer villages and/or can support more other terminals. The reason for this is that you only need to actually play half of your mighty nice draw cards every turn, even while reaping the benefits of those you played last turn. So when I build a wharf engine, I usually start Wharf-wharf-village-wharf and then alternate. Well, okay, usually it's more complicated, because I want to get other stuff, too, but you really don't need that many villages to support the draw part of your engine. And the +buys are very nicely and plentifully built in.
And now, a word from our sponsors about trashing. Trashing helps you here, as it does with most engines. But enormous trashing isn't as big a deal here as it often is, as you can easily end-up over-drawing, and you don't have that much time to out-run the big money. Furthermore, you generally want your trashing to do something useful for you later on. So remake has good utility, as does steward. Chapel a bit less so. Ambassador, as normal, is good (but watch out for wharf/money decks - they can soak ambassador attacks pretty well). But something like lookout, moneylender, spice merchant, trade route... well, it's not that they're useless. But generally, the plusses they give you are fairly minor for the time investment, given how much you have to put into them anyway.
Okay, but what other stuff can make you want to go engine over money with wharf? A LOT. Coppersmith can be worth its weight in gold pretty often. Outpost hands are at least normal sized, often larger. Any kind of discard attack is good - you won't need many copies of it. Cards that like big handsizes are good too - bank is still great here, forge can be, etc. Indeed, most kinds of cards with nice effects will make the engine at least reasonable. Some won't - cards like minion and lab don't do you nearly as many favours as they normally do, something like fortune teller is still weak, and tactician... well, you're basically losing half of wharf's advantage with tactician. Which doesn't mean it's never worth it, but once again, it's comparatively much weaker.
Works with:
Bank
Fool's Gold
Crossroads
In engines with coppersmith, outpost, most anything good.
Doesn't work with:
Hunting Party
Lab
Minion
Most other terminal draw
(It's not really that ^^these things are really actively bad, just they don't really help, at least not nearly to the extent they normally do)
Tactician
Mega-rush strategies, like Ironworks/Gardens
