Post your carabiner thread!
I have a decent sentimental attachment to my key ring carabiner. It's not locking, but it is a nice Petzl that still has enough snap in the gate after years to make me feel secure. The only issue I've ever had is if I put my keys in it a bit too fast and they sit right where the gate closes, preventing it from closing, and letting the keys jump out. But, this would be a problem with any carabiner; solution is just to check em.
There's scratches all over mine from a crash, the anno on the gate is mostly worn off, and all the edges are polished smooth. It holds my keys, I love it!