This is an excellent series with great animation and some utterly brilliant characterisation.
However, when originally broadcast, it was played deliberately out of chronological order. The DVD release places the episodes in chronological order, so new viewers might wind up with a different experience of the show than was intended.
I've seen the show in broadcast order, and think that it's actually something that'd make a big difference to the quality of the show across the series.
This means that the DVDs will work best for those who have already seen it, and for those content to skip around a bit. The list of what episodes are played in what order for the original broadcast, and how they've been moved for the DVD, can be found here, or if that page moves, here's the Wikipedia list. Note that the Wikipedia list also discusses episode content and the wider series, so I'd suggest just looking at the titles.
I'm sure the DVD quality is excellent aside from this odd decision, and even that's not a huge deal providing people go into things with open eyes.
Apparently, the Special Edition DVDs contain an extra disc from Volume 2 onwards with all fourteen episodes in broadcast order, although without an english dub.