Question How to upscale emulated video game videos?

I had been recording gaming videos from emulators from time but I still have some questions that I wish to ask. I had been using a method where I did two resizes in Virtualdub where one resize (Nearest Neighbor) was to upscale the video and the other resize (Lanzcos3) to maintain the aspect ratio. While this method had served me in the past, I realized that it may not work for all the games I want to try out. I really want to know what is a good way to upscale these games:



I like Spryo as a kid but I do not know how to properly upscale a game like Spyro or any game from the fifth generation of console for that matter. Can anyone give me advice on how to upscale something like Spyro without getting into artifacts? Can anyone give some alternative methods that will allow me to upscale games from various consoles without comprising the quality?