This thread is not a joke thread. I love Scout jokes. I really do. A little too much, actually. But this thread is about quirky combos that make one of the worst cards in the game stand out as doing something in a sort of above average kind of way. Since this is a tall task, I might overestimate a combo, but I'm trying the best I can here.
Warehouse/Tunnels/Scout
The "Scout + Intrigue" combos have been sort of meh in my experience. This combo actually makes Scout medium-strong in context. Open with Warehouse and Tunnels. Pick up a Scout or three eventually, but have more Warehouses and Tunnels than anything else. You'll have Provinces to draw pretty early, too. Gain more Golds, and have enough money in hand to buy Provinces on turns where you gain Golds. Yay.
If you can get a Crossroads or two in the mix too, then it can get crazy (if not totally consistent). Ideally, you'll be trashing your Copper early as well.
Possession/Scout
I read about this in another thread once. Not exactly a combo, but Scout is one of the best cards to have in your hand when you want your *next* turn to be a lot better than *this* turn. That's a backhanded compliment to be sure, but in a Possession game, this has been reported to be a legitimate strategy. Slog through the Duchies and alt VP. Maybe snag a Possession for yourself too - I'm not sure or it depends on the board.
Admittedly, this isn't as good as Rats/Bishop or Militia when it comes to cards your enemies won't want to play goes, but oh well. You have to take what the board gives you.