For better quality you can use a component transcoder or an rgb upscaler, but that depends on what kind of signals you are starting with. The one you linked is better for saving space if you only have a couple of signals and you want switchbox functionality (looks as though that is something it does.) It all depends on what you intend by "best." I added
this 
to my computer when all other options failed to deliver a clean centered image from my XBOX to my older LCD projector. This option was best for me because almost all my consoles sync to it, and even my jamma games (with some effort.)
Your best solution, if image quality is a major concern, may also depend the type(s) of display(s) you are going to use.
First I tried a standalone option for PS2 and XBOX to a VGA setup similar to
thisI payed $40 for mine, though. It looks almost as good as my sweetspot on my CRT and my newer projector but the image was off center on my older LCD projector no matter what end-user adjustments I tried on each of the three devices.
BTW, I know these options are technically not considered VGA-boxes.
The DC outputs a beautiful VGA with the official box or the official vga wire or equivalents.
For an all always connected setup( you could get the transcoder, a component switch, and the dreamcast VGA cable, and a KVM. Or alternatively you could get three 15khz RGB cables, a three input switch, and an upscan converter. You can get Pure VGA out of the XBOX if you have the right version and you are very hacky.