Agreed. It will be different for each couple.
My DH and I opened a joint account shortly after getting engaged. We each kept our own personal account. We each put a set amount into the joint account for bills, savings and joint fun. We have personal account to spend as we please - fun, gifts, etc. It's our mad money. A few times a month we discuss bills and where we are at with our budget. It works very well for us.
As long as you and your significant other are on the same page, then that's all that matters. 
Starting Score: TU 590, EQ 627 (2/6/12) ~ BK filed 5/2011