Pretty much just Butcher Shop with SanSans, but I've made a couple of innovations. One of them is just because I love Viper. The other, though, is worth mentioning. Kids, meet your new step-mom, Private Contracts. (Or as I call it, because I'm a lawyer, PriK.)
After seeing some Butcher Shop players going down to two Marked Accounts and playing weird stuff like Restructure instead, I tried switching one Marked for one Contracts and loved it instantly, and never looked back.
Yes, it's true, Private Contracts will make you a finite amount of money, and pays out less money per click, total, but it has two major perks - it pays out as soon as you rez it, and it pays out as soon as you want the money. Think about it this way - the runner must face the same cost to trash either card when it's face down, but with Contracts against, say, Whizzard, you can immediately rez it and triple-click it. Now you've broken even on the 4 clicks - three credits and a card - and your opponent now has to decide if it's worth it to pay 5 credits/2 + 3 Whiz credits basically just to deprive you of 4 free credits. Most runners wouldn't go for that. Whereas with Marked, against Whizzard, they get to pay 2 credits to trash it after you rez it, and all you've gotten for your two clicks is a single card.
The other advantage, of course, is it gives you money when you need it. (It's like you're running one of those companies that buys up people's annuities.) On balance, it's not a big difference - free credit from Marked + 2 clicks for credits + Midseasons is only 1 less credit than 2 Contracts clicks + Midseasons. But sometimes, one tag is the difference between, say, two tags - manageable for the runner - and three tags - danger zone.