In Australia I've got 100 down about 3 up 500gig with Telstra. Pay $129 a month to not have it bundled with phone/TV.
Most internet packages start at around 20gig a month for around $40 here though, so young families will go well over the cap just from patching games.
We used to have a lot of companies with unlimited caps in the early days, but the fear of piracy caused many to abandon unlimited and force customers into caps.
Some providers have deals with Microsoft to allow unmetered data from their services but their only on adsl so speeds are poor.