Mmmm ... Lipton Onion Soup burgers ... reminds me of childhood.
While I don't have a stand-alone grinder, I have found that having my butcher grind it fresh for me (rather than the family packs from Kroger, etc.) makes a difference. He advertises a "burger blend" that's a grind of 60/40 sirloin and oxtail. He charges a premium but it's really good. He does sell patties with bacon ground into it but I like the textural difference when semi-crispy bacon is on top of the hamburger patty.
If you're looking to mix things up from a taste perspective, I'll usually mix in garlic powder, fresh ground black pepper, and a few dashes of Worcestershire into the mix when I make the patties and let them sit in the fridge a bit to firm up before cooking. A cast-iron skillet is the best way I know to cook a burger; I've never liked grilled patties as I think they lose to much moisture. Getting a good crust on the patties from searing is great for texture and goes really well on a pretzel bun or even a King's Hawaiian bun.
I know this isn't exactly novel but I really like the blend of meat I'm using for this and it's worth a slightly higher price, in my opinion.