I haven't bought new tires for quite some time except when I got myself a set of lighter wheels.
I usually use my tires until they fail. Sadly they give up when they are overinflated to save mileage but that is because they are just taken off the clunkers at the junkyard or recycled from the used tire yard at dealerships/auto shops. Saves me a lot of bucks but they just last a year so I keep an eye out for people who replace their tires and ask for the old ones. (neighbors and coworkers included)
Here are some of the tires that have bitten the dust:
