Well seeing that you asked for red wine ... the most obviousl answer is a well made red wine from a decent vintage in a style that you like...
Ex... try France - Bordeaux, Burgundy,and Southern Rhone.. most wines that are easy to find, are decent, and likely to last will cost $50->
... but most regions these days make wine capable of improving with time.
Take a look at a Vintage Chart
and look for a region that produces wine in a style you appreciate that is rated well.. Sign up for a free cellar tracker account and you can get reviews and predictions on any wine you are looking at or just google the bottle.
If you pick a region, style,and price there are tonnes of people here that would point out some good suggestions.