Indeed, as B_T already answered, there are many HuCards that justify the purchase of a CoreGrafx. Lots and lots.
In fact, too many people discount the HuCards in favor of the CD-ROM games, IMO. It's a damn shame.
What genre(s) do you find particularly interesting?
If you dig shoot-em-ups, then it's a no-brainer. CoreGrafx = happiness.
If you only like RPG's / action-RPG's, well, then, you'll be lusting for the CD-ROM titles...