X-Com and TFTD were great. I had X-Com on DOS and, later, my brother had the PS1 version.
The PS1 music was great*....but man those load times were painful.
At least the PS1 version fixed the difficulty bug that DOS had, though. After your first ground mission the game would always revert to beginner for the rest of the campaign...regardless of which of the five difficulties you chose.
TFTD released on PS1 as well...but only in England and in limited amounts. It's one of the rarest PS1 games out there. (So is X-Com: UFO...but not to that extent.)
As for the modern XCOM...yuck...just...yuck. So watered down it's not even funny.
*BONUS

