What is the fastest way to remove green screen in video?

This produces a near perfect key just by importing it into AE, adding it to a composition and throwing on the Keylight effect, then sampling the green with the eyedropper. All that is required is to crank up the screen gain and then one could of course go in deeper and finetune the alpha rollback a bit and a few minor other things. I was a bit skeptical at first since the green looked too yellow-ish, but it really works, at least based on the sample clip that could be downloaded. So if you feel like it, you can dive in straight without having to fear much. I'd only recommend a slight color correction after that to get rid of the yellwo shift, which can also be done with a basic Color Balance effect and tweaking the Midtones Red/ Green balance.

Mylenium

There's no simple answer to that. The available keyers work differently and outside that of course the type of footage matters, your overall experience level and so on. Keylight in AE can be great if you know how to reign it in, but so is the Premiere keyer or tools like Primatte. It's really not a question if A is better than B and which takes longer to learn. If you can provide a screen shot/ reference frame of your foootage we may be able to advise, but even then what's obvious to us may not be the best solution for you.

Mylenium