I actually played Conker's Bad Fur Day for the first time in years the other day, still had lots of fun playing. 4 of us also played the multiplayer game "Beach" and we had a blast.
It is true though, some games just don't age well. One game that I still go back to and play once a year is Brigandine, for the PS1. It got bad to mediocre reviews when it came out, but my brothers and I always loved it. I've considered getting Brigandine: Grand Edition from the JP PSN and try and get through it without being able to read the language.