Jester King has a couple though I've not had the pleasure. There's Russian River. Allagash makes some pretty damn good sours now. There's the Leifman's beers from Belgium. For an easy to get and readily available lambic/gueuze I like Lindemans Cuvee Renee (not sweet at all). Then the other Belgians like Hanssens Artisinal, 3 Fontenin, Tilquin, Oud Beersel, Mort Subite, and Cantillion. Some are easier/harder to find and some put out sweetened lambics with a rarely seen standard lambic product. The classic Rodenbach Gran Cru is tough to beat for price especially when compared to state side craft brewery offerings. You can buy a 750ml bottle of Rodenbach Vintage for the price of many US produced sours in 375ml bottles. Jolly Pumpkin is usually pretty affordable and has a good selection. Ithaca Brewing out of NY also makes sours or at least used to. I almost forgot about The Bruery but they can also be just as spendy as Cascade bottles.