iMovie alternatives are plenty for Windows. Premiere ranks up there at the top, but there are plenty of others out there.
Google has its own video editor for when you want to upload to youtube. For bare basic with more plugins then you can shake a stick at, Virtualdub is tried and true. If you want a more updated look and feel program, then Avidemux might be more your thing. However, if you are looking at software that has a pleasant palette as a criteria, then your not looking at software to get the job done, and want eye candy to stare at. Two other's that you should really look at is VideoLan Movie Creator. It does everything you need plus a pleasant palette! And the runner up and the software that I use is Avisynth.
Now Avisynth is a frameserver, and is not for the beginner. There are plenty of frontends for it. Avisynth can even use some Virtualdub plugins. You use it with a handfull of other tools to get great results, each tool doing better then some One click wonders (source, output, click run).
Now one last thing, MKV is a widely supported format. I use MP4, but MKV can hold it all! supported by hardware vendors, and used nearly exclusively by Anime subbers. There is no hate invovled. Please be more informed.
~Majorlag