PSXeven is a free PSX emulator running on Microsoft Windows devices. The emulator was developed fairly fast, but it was abandoned just as quickly. It went through a series of updates over a short time frame, gaining reputation as a promising emulator. While excellent at improving the speed, the emulator tried to bring in some extra accuracy and stability over its last versions. The best part about it? Apart from running most PSX games out there, PSXeven was also appreciated for its super simple interface. It also came with a few handy features that most other PSX emulators provide in a separate way.
For instance, PSXeven came with a built in memory card manager, as well as a tool to compress game images. It relies on a plugin system and you can still find it for free over the Internet. The PSX Bios is the main requirement to run the emulator though.