Recently I've got Datapath VisionRGB E1S, seem like some medical equipment supply store on ebay has put up a number of used ones relatively cheap. I have to say out of all the other cards I tried before I think this is the best I've got so far. It can capture digital or analog via DVI-I port, it's switching resolutions very fast, 70hz for 'legacy resolutions' as well, RGB24 for proper colors and various other nifty things like forcibly maintain custom defined aspect ratio (like 4:3). However it's not ideal either. First of all it doesn't do audio capture, only video, you gonna have to use a separate audio card and potentially deal with a/v syncing later in post-production stage. It doesn't work with OBS studio, but there's a plugin for OBS classic which I have not tried yet. AmarecTV does work but shows image flipped vertically. Datapath provide simple output display application and the image is really good there. I don't even use XPC-4 with it.It has own RGBeasy API and perhaps there are more useful things there (vvbee's links above seem all went 404) but I've yet to check it out, hopefully there are ways to customize scaling filters and other nifty things.
The Micomsoft XPC-4 is a video scan converter, not a capture device. The Micomsoft X-CAPTURE-1 is the same as the Startech USB3HDCAP.
Yep. Which in turn are based off Yuan-Tech capture cards line up.
Recently I aquired the AverMedia Live Gamer HD Lite and to my huge surprise it can capture crystal clear signals via Rec Central. The trick is to use an AGP card with DVI port on your Retro PC like in my case the Nvidia FX5900 and connect a DVI-HDMI cable from your AGP card to the Live Gamer HD. It can transmit even the bios bootup so I highly recommend it if you are on a budget.
Of course it'll be crystal clear - your DVI output sends digital signal and that's what your capture card receives, it can't do analog anyway. No surprises there. But a few downsides are: it'll be left up to a graphics card to scale the output to resolution the capture card will use, and often times there's very little control over how this goes. Your graphics card essentially becomes the scaler unit in the video chain. Unfortunately this isn't an option for older cards without digital output, not to mention prices on something like V5500 Mac aren't funny at all.