Age of wine

[etr]

I have various bottles of wine dating back to 1997.

How can I tell if a wine is worth keeping or if it's better consumed when bought?

Thanks! (Thanks for the Beaujolais tip)

[Innkeeper]

Almost any red will still be good, and some may not even be ready. Please list any you are not sure about. Most whites will be beginning to fade, and a few will be gone.