My favorite monopoly games are those where the players have played together before, and agree on a set of custom rules to the game in advance, and are fast-paced. I remember having rules added like loans and interest, and effectively unlimited freedom to make deals with players. Deals logged on paper, loan interest measured in turns and percentages, so much...fun. Actual fun though.

A game like this can even go fast paced where the next player is making their turn while you're still interacting with the bank from your turn, while someone else is calculating interest.

Doesn't sound fun typing it out but it was a blast.