As other reviewers have commented, the producers chose to do this episode far too early in the series. The idea -- some mysterious disease infects the crew and they all start behaving inappropriately toward each other -- is not a bad one (after all, it was used in at least 2 other Trek series), but it only makes sense once you actually have a good sense of the characters themselves. That's impossible only two episodes into a show.
The first time I watched this episode, the word "awful" came to mind. The second time, my opinion improved -- but it's still not very good. Despite some ham-handed attempts at drama, the "serious plot" is worthless. Most of the jokes are not much better. The best parts (as on many early TNG episodes) center around Data; his romantic encounter with Tasha Yar is a classic of the series. There's also the hilarious sequence where Wesley takes over the ship ("Acting Captain Wesley Crusher"). There's some nice chemistry between Gates McFadden and Patrick Stewart (this could have been really good from season 3 on).
Aside from that, this episode contains most of the bad qualities of the early TNG -- mediocre writing, bad production values, cheesy music, and some stuff that is just flat-out bizarre (why would the rapidly expanding layers of an exploding star look like an asteroid?).