My favorite stand by is Samuel Smith oatmeal stout.
Can't really go wrong with any of the true trappist ales, although there's a good reason rochefort costs that much, so treat yourself at least once.
If you have a sweet tooth, or have a lady who likes sweet wine, any of the linemans lambics are better than dessert. I'm partial to black current. Pretty much anything from belgium is hard to go wrong on.
For a summer beer, I really really liked one called new amsterdam ale, but the brewery went out long ago. It was perfect in its hoppiness, never found something close, so I'd like to hear about an ale along the line of pete's wicked, only much smoother in taste and smell. That was what the new amsterdam was like. Since it's gone, as a lighter hot weather brew, I like Carta Blanca.
I like sampling new beers, especially on trips, but ultimately, it's much more fun and you can tailor your tastes by brewing your own. My alltime favorite is a pumpkin pie stout that I concocted for the first time maybe 20 years ago. Moved and kind of got out of brewing, but still have people ask about that stout. Been experimenting with fruits past few years, making my own hard cider and did a peach liqueur from an old farmhouse recipe last fall.
Fermentation rox!