It depends on what kind of bass you're looking for and how much space you have to spare.
Sealed boxes have a smaller air space requirement then ported boxes so Sealed boxes are much smaller than ported. From the Sealed box you will get a tighter bass and somewhat better sound quality.
Ported Boxes require more air space and take up more of the trunk area than a Sealed Box. The bass from a ported box is generally louder than bass from a sealed box. What I mean by louder is it will take less power from the amp to get more bass from a ported box than a sealed. And if the box is tuned properly can also have good sound quality in certain frequency ranges.
I run sealed boxes because I like the tighter bass and the smaller size that the sealed box produces.