As title really. Had a fairly expensive Weber one, cracked (someone put it in the sink...) then a cheap thin one (£6 with a metal stand) (cracked, cheap and thin).
Now use a black granite chopping board think it was £12 from Tesco. Scrape off the rubber feet, give it a good scrub then use the matt side for baking on. Always bring it up to temperature with the oven. I never immerse it in water, just give it a good brush down. Fits the oven rack perfectly and really helps with home baked pizzas. (PS I use the the Silver Spoon dough recipe - 00 flour, yeast, salt water, no oil).