Amazon's Best Books of the Month usually has a good list of recent books to check out. Their "100 Books to Read in a Lifetime" list is also SUPER solid. One of the most solid book lists I've ever seen, as far as my personal tastes go. I've read around 50 of the 100 and of those I've probably liked and enjoyed 90% of those.

I hit up "Best Of" lists a lot, like just the other day I went through Book Riot's Best Books of 2015 So Far.

Goodreads I find is only really good for Young Adult recommendations.

I'll also do google searches with two books I love but are very different to see who else has liked BOTH books and what other books they liked. So I'll search for both "Bel Canto" and "Born to Run" (two completely different genres, both books I loved) or "Dune" and "My Life in France". This way I can sort of stumble across a book blog or a list that has both books on them and I can also trust in the taste level of that person or list.

I also will occassionally browse places like Reddit Books or Ohnotheydidnt to see what people are reading. Reddit is usually only good for Science Fiction or Fantasy recommendations given the demographic, and Ohnotheydidnt is GREAT for finding feminist/female lead character books.

And then once in awhile I'll just dip into the classics.