we have a few different gates...we bought the cheap ($20) ones you can get at Walmart that fit to a specific size door. We bought a more expensive one that swings open and close for the one entry to the kitchen (so we didn't kill ourself climbing over a tall gate)...we also have xpens that can be used in pieces to block larger doorways. It's all dependent on the layout of your house in my opinion.
P.S. We found plastic xpens cheaper on amazon.com than in any store.