We have a very elaborate set up. We have almost all joint accounts, but two accounts are designated as "single" accounts. 10% of our paycheck goes into these accounts for discretionary spending that the other cannot monitor or say anything about.
As for everything else, I'm in charge of paying the bills and such. Each week I do a simplified spreadsheet for my husband to look over that says the balances in all the accounts, any debt, and what bills are due for the week. He approves everything and any money left over he decides what it goes towards.