The best places to get chunky funky sweaters are thrift stores (for example, this one). They're perfectly oversized, just the right amount of worn in, and come in unique colors that are often hard to find. And just like denim, the best sweater is someone else's sweater. If that doesn't gross you out.
I sometimes double this one as a jacket but this time I wore it with classic stripes, light jeans, and classic black flats. And I just looooove this color (three sweaters and counting).
Sweater: Thrifted (similar)
Top: Gap (similar)
Jeans: Urban Outfitters
Flats: Urban Outfitters (really want these)
Sunglasses: Free People (similar)