GUTS are you sure you aren't confusing Xiphas with NASAchusetts? NASAchusetts plays Snatcher every year around Christmas time, fits perfectly.
There are only so few digital comics I can comment on since the vast majority are in Japanese, but it is a blast to play through what's available.
Snatcher - The best obviously. To spark debate here, which version?
Shadowgate - Not sure if others would consider this a digital comic, but I do and it's classic.
J.B. Harold Murder Club - Another game that some might find hard to consider a digital comic, but a fantastic game nonetheless thanks to the amazing mystery solving.
Famicom Detective Club 2 - I nearly completely agree with GUTS on this one.
Games that look promising:
Dead of the Brain 1 and 2 - Ever since I saw videos for it on some really weird Brazilian PCE site (no not UNIVERSO PC ENGINE), I got excited to see how cool and spooky it looked! Hopefully the translation will finish.
Cobra and Cobra II - Black_Tiger gives much praise to these games saying they're (or at least the second) better than Snatcher.
Blue Chicago Blues - Another J.B. Harold game except this case takes place in the radical city of Chicago! Me and Xiphas are eager to play this one, but the problem is that the English versions are harder to come by. What systems are the English versions for again? Laser Active is one...