Then "too bad", it goes to goodwill!! My mom did that, but I think she's realized that the tons of plastic crap she's brought over here is NOT HERE ANYMORE! It just disappears... So, she stopped bringing it, and her compromise is if she buys anything noisy/obnoxious, it stays at her house. I'm an adult now and she can't dictate what's in my home. Unfortunately, ds has realized this, and now begs grandma to bring HER toys over whenever she visits. We live in a townhome too- a tiny one, so I also use that as an excuse when she gets something huge and crazy- sorry, no room, keep it at your house.
I just remember what my room looked like as a kid... broken toy pieces everywhere, couldn't see the floor, didn't play with a tenth of it, didn't even know what some of the pieces went to, etc. I do NOT want that for my kids.