There's definitely one huge plus that comes with watching anime a few years after it has seen release. Usually by that time, an entire series has been released in Japan and localized for the states. You can't beat the feeling of finding out about an anime awhile after it's concluded, and then picking up the entire series for viewing. It lets you wrap things up on your own terms!
The opposite of that comes from watching anime that is only just now airing in Japan, or is only just getting localized now. Finding an anime series you really love can be an easy thing to do, but waiting for the next DVD release or box set can be an excruciating feeling. You could be left hanging for the next round of episodes for a number of months, and sometimes you don't even have a date for a series' return!
Indeed it's similar to watching regular TV shows, in the sense that you have to wait for the next season to roll around before you can jump back in. With that said, the wait for another DVD release can actually end up being much longer than that of a regular TV season. Even worse, most TV series in the states have upwards of 18 episodes a season. With anime releases via DVD, you sometimes only get 5 episodes a disc! Waiting 3 months inbetween 5 episode stints makes things quite intolerable!
There are indeed ways to feed your need for that series, such as watching episodes online via fan-subs or stuff like that. Of course, some of that stuff is not exactly the most legal way of viewing. I like to keep things legal and watch as they're officially released. As much as I want to see another episode, I don't want to hurt the publishers that are working hard to make it happen.
How do you deal with the torture of waiting for the next episode of your favorite series? I guess supplementing your time with a second anime might do the trick!