If you're interested in reading what it says, here's the warning Emulator Zone have up right now: Making that clear from the get go seems pretty sincere to me, whereas sites that trick you into doing surveys and stuff usually don't have banners like that on their homepage. They seem pretty trust-worthy because the first thing that is posted on their website is a warning about how this kind of software is kind of risky and there are a lot of fakes out there.
When looking for emulators to use with any console games, I usually stick with Emulator Zone