I'm assuming we're all talking about a desktop. If so, let me give my opinion.
I'm not sure if this issue has been solved, but I remember installing Ubuntu 10.04 and not being able to connect to the Internet from my desktop. It connects to the Internet from my laptop perfectly, but not from my desktop (granted, my desktop is ancient if compared to modern systems). Apparently, from what I have read, some wireless cards don't work with Ubuntu, making Internet connectivity an issue. This may have been solved (or it may have been my machine with an issue, one of the two), but I suggest looking into this before definitively installing Ubuntu.
Let me just tell you that I'm a newbie when it comes to Ubuntu, so I ask you not to take my word for it until you find out more about it. Ubuntu is a very refreshing OS and, with or without Internet connectivity, it's something new.