I've tried all kinds. Most just don't stay in at all. Foam, silicone, plain, ribbed for her pleasure, and I think I tried the moldable kind once, and even that was an absolute failure. Earbuds for iPods and such, forget it -- it takes me more time to get them situated to where I can hear anything out of them and they don't fall out, by the time I get them in I'm too aggravated to listen to anything.
These Sonic Defenders are actually the first pair I've gotten to fit in easily without fighting and having to stretch and contort my ears every which way to get them to stay. They slide right in place, with just a little tug on my earlobe and an extra nudge to seat them. They even feel like they're pretty flush where they're not sticking out. All by themselves, they feel like they're in there good and secure and block out a lot of noise -- they'd probably be awesome if I didn't have to wear a snug-fitting helmet. But they come loose pulling the helmet down. It's not because the helmet is touching them, it's just the way it pulls on my ears as it's going over that it opens them up just enough that whatever is in them falls out. I may try again, maybe try to nudge them in a little deeper, if that's possible without injuring myself. But it isn't supposed to be this difficult.
