"Haven" is the episode Gene Roddenberry was probably waiting for since the start of Next Generation, in which he finally gets to reclaim a subplot from The Motion Picture. Riker and Troi's relationship gets shoved to the front, the element of the series borrowed from Decker and Ilia. Thankfully the second incarnation has a more humanly happy resolution.
If there's an obvious flaw to "Haven" for long-term fans, it's most of what is established about Betazoids in the episode really doesn't end up mattering, other than a few cultural points (and the term "imzadi," which becomes the title of a book by Peter David about Riker and Troi's relationship, popular enough to warrant a rare sequel). The series doesn't really "get" Betazoids until Troi's cloying mum, Lwaxana, begins to dominate later on. Lwaxana does debut here, in the guise of Roddenberry's widow Majel Barrett, but if you have any memories of "Haven," perhaps it's of a young Robert Knepper (later to achieve notoriety in Prison Break) or Armin Shimerman making another early franchise appearance as the face on the side of a gift box (seriously!).
Either way, keep your focus on Next Generation's premier on-again-off-again couple (better at it than Picard and Crusher, who do get the series finale as a spotlight consolation prize), Riker and Troi, particularly Troi. "Haven" is a little like "Amok Time" in that it features Knepper as Troi's intended suitor who doesn't end up working out (much like Worf, but that's another reference to the seventh season, which is a long way off, although if Worf were the suitor, or in Troi's line of sight here, you can bet we'd have another memorable fight on our hands).
More importantly, the episode positions Troi as more significant to the series than the first season tends to suggest. She also steals "Skin of Evil" from the death of Tasha Yar, by the way. In that way, it may be another sign that the writers needed to concentrate on things other than what they were bothering with at the time in order to figure itself out. This is ironic, because here it's something Gene Roddenberry wanted. By the third season it's basically other stuff.
franchise * series * essential * character
Carel Struycken (Mr. Homn)
Memory Alpha summary.