DH and I have been together 19 years.
We have our own bank accounts. We both earn similar amounts (he earns slightly more than me, but not enough to matter hugely), and so we have a joint account that we put an equal amount in which covers household expenses - bills, childcare etc. We also have a shared savings account that we put the same amount into.
I pay for groceries. He pays for takeout and restaurant food. As a rule, one night a week we'll either get lazy takeout or will have a date night (he also pays for babysitters).
We have no fixed rule for holidays, but we probably pay 50/50. I guess with clothes and other stuff for the kids which isn't a fixed regular amount, if it's a small thing we both randomly throw in our own money or sometimes we'll transfer it from the joint savings account, which we both put a fair amount in. And we've never really argued and I think, again, it seems to work out.
We pay for our own cars, phones, clothes, hobbies etc. I prefer it that way. I cringe when I see people talking on MN about how their DH spent 'family money' on something they don't approve of. We have family money which covers our family bills, but once that's covered, if DH wants to blow £100 on a pair of trainers, or I want to blow £80 on a new lens for my camera then as long as the bills are paid and the kids are fed, then that's our own call. I'd hate to feel like I needed to justify how I spend my money that I earn as an adult. And it is my money. I got married. I didn't become part of a gestalt entity. I also really like not having to feel like I'm responsible for another adult's spending.
Obviously, other people do things differently and that's great, but we've been perfectly happy doing it this way for 19 years so I figure we can't be getting it all wrong.