I used to use a big $400 rolling case. it really limited what I was able to do, partly since i live upstairs and partly because i didn't always want 4 lights on a shoot.
Now I use baseball deck bags. Very similar to this:
Most 10' light stands are the length of a baseball bat when folded up. Most monoblocs are less than the size of a baseball helmet, so the important parts fit easily.
Most bags also have LOTS of pockets for various bits and modifiers.
I used to use one for 2 monolights and modifiers (for an outdoor kit), and one for one monolight and several speedlights (for an indoor kit).
However, 2 monolights, stands, and modifiers are way too heavy to go into one shoulder bag, so i'm going to one monolight per bag.