My son is so new to his Troop that I haven't figured out yet the complete picture on how they fund the program, so I'll answer in regards to the Pack I've worked with.
The Pack serves some of the poorest schools in town, so we only started charging dues last fall and only $12 for the year (on top of the $24 national recharter fee and optional $12 Boys Life). This isn't a significant amount - not even enough to fully cover awards and rank badges, but we felt that people might value Scouting more if they had some money invested in the Pack.
Our primary fundraiser was popcorn. As much as I've grumbled about selling it every year, compared to Girl Scout Cookies a lot of money came back to our Pack from the Council - close to 40%. Our Council's vendor, Pecatonica River, does a great job of supplying Tasting Kits for our Popcorn kickoff, signs, etc. There is no risk to our unit (as long as your popcorn kernel pays attention to the important dates!).
Plus, the best thing about the Popcorn sale is that a good chunk of the money is what funds our Council. When your unit sells something other than popcorn, remember that you aren't doing your part to fund your Council and its camps. I know some of you will say that you don't use your Council's camps, but remember that if you are using some BSA Council's camps that somebody has to pay to maintain those camps, and if all units had that attitude none of our Council's would have camps. The summer camp fee you pay goes toward Program(staff, food, supplies), not Facilities.(Camp buildings, Ranger to guard and maintain it, camp improvements and maintenance, etc.). Camps are our Council's single largest budget line item, and the popcorn sale is the biggest chunk of our Council's annual budget.
Now, with my plug for selling popcorn out of the way, the other Fundraiser our Pack does every year is selling popped popcorn at our Chartered Org's annual Car Show. We sell popcorn for $1/bag and generally pull in a few hundred dollars. It isn't a lot, but it isn't bad for one day's work. We've also dabbled with a few others like selling candy bars, and thought about a brat fry or something similar, but haven't really had the need with a few years of good popcorn sales.