If you're looking for an overview, I very much have enjoyed Bertrand Russell's The History of Western Philosophy. You have to take a lot of his history with a grain of salt (because he was no historian to begin with, and our understanding of the history of basically the entire book has changed a lot since he wrote it in the 1940s), but his discussions of the philosophical content are both clear, learned, and intelligent. He has his particular points of view (he thinks Aristotle's ethics are a waste of time for anyone today, for example, but he does discuss them at length), but he still outlines very clearly what was being said, what others were saying at the same time, and tries to be charitable in considering how the historical speakers would address present-day criticisms. It's the best "overview" book I've read on this stuff: not so much detail that you need a degree in philosophy to make sense of it, but also not as "fluffy" as some "philosophy for dummies" books are (which don't really teach you anything). Russell is also a very good writer (he didn't win the Nobel Prize in Literature for nothing) with a wry sense of humor, which helps, and each chapter is not very long, so you feel you are making a sense of progress despite it being a 1000 page book.

The first third of the book covers Ancient philosophy through the Roman empire. The middle third covers medieval philosophy, largely Catholic philosophy. The final third covers "modern" philosophy, which for the 1940s means the Renaissance (e.g. Machiavelli) through the 19th and early 20th-centuries. I found the first third the most interesting, but the rest is worth the read as well.