
Kitsis and Horowitz really outdid themselves with Tricia Tanaka is Dead, which I consider to be the funniest episode of the entire series. It's also got its share of emotional moments that grab you when you least expect it.
The first such moment is right in the opening scene, when a skinny pre-teen Hurley learns that his father (David Reyes) is leaving. So much for their shared project of restoring a Camaro. David gives him a candy bar as consolation — quite possibly the moment Hurley begins to substitute emotional anguish with food.
The Camaro becomes the metaphor for Hurley's relationship with his father, sitting on blocks for 17 years and representing unfinished business. By the time Dad returns, Hurley's a mega-rich lottery winner who can't trust his motives. Too much damage has been done; all Hurley cares about is getting to Australia to study the source of the Numbers.
When Hurley discovers an abandoned DHARMA van on the island, nobody shares his excitement. Jin and Sawyer end up helping his cause to get it running again, which results in some of the most hilarious sequences in the entire series. I won't even try to list them as it won't do them justice, but suffice to say Jin and Hurley's language barrier sets up one joke after another, then Sawyer chimes in with some entertaining English lessons. We find out later that Roger's last name is "Linus", but to many LOST fans he'll always be "Roger Workman".
Hurley's crazy idea to start the van puts his and Charlie's life at risk, but naturally they emerge victorious. This triggers an emotional ending that's simultaneously uplifting and heartbreaking. I rejoiced at Hurley's success — much like Jin raising his arms and shouting "Hurleeeeyyyyy!" — but the follow-up montage with Hurley sitting alone in the van got the best of me. Big time.
To those on the island it seemed like Hurley only needed a few hours to fix the van. As far as I'm concerned it was a work in progress for 17 years.

Jorge Garcia really struggles when it comes to emotional scenes but he really shines when writers leverage what he does best — comedy. To illustrate this all you must do is compare two scenes: 1) Hurley visiting Libby's grave and 2) Hurley and Jin tipping over the DHARMA van. The former scene is uncomfortable due to some shaky acting, the latter is hysterical. I burst into laughter every time I see Hurley gesture at Jin and yell "I UNDERSTAND!".
Ironically it was Garcia's narrow emotional range that helped his cause at the end of TTiD. When he's sitting alone in the restored van it was practically poetic that he looked stoic and expressionless, like he was determined to suppress a wave of emotion. I also loved the aggressively determined Hurley, the one that smacked Charlie around and challenged him to look Death in the face and say "whatever man".
Daniel Dae Kim was brilliant in this episode. Check out his reactions when Hurley recruits his help; if you've ever talked to someone who didn't understand a word you were saying, you'll know his facial expressions were flat-out perfect. It can't be easy for a native English speaker to portray a man struggling to learn the language, yet he's completely convincing in selling the difficulty of Sawyer's lessons.
Speaking of Sawyer, this is one of the few episodes where I really liked the character's contributions. Don't misunderstand me, I think Holloway himself is consistently a great actor, but this was a shade of Sawyer that had me in stitches almost as often as Hurley. The first time I heard him call Hurley "Snuffy" I missed the next few lines of dialogue from laughing so hard.
Lillian Hurst (Carmen Reyes) is the perfect casting choice as Hugo's mother, especially since I'd put their acting abilities in the same category. She's not the most gifted actress you'll ever see but when it comes to comedy she gets it. Covering the ears on the Jesus statue before she talks about her "needs" is comedic gold.
Cheech Marin (David Reyes) is yet another great casting choice for the same exact reasons: not the best actor by any means but he's obviously established in the comedy arena.

The legacy of Tricia Tanaka is Dead's visuals will be this: one very expensive effect, lots of minor-yet-cool effects, and one really, really bad case of editing.
Expensive effect: the meteorite smashing into Mr. Cluck's chicken shack. If you believe Kevin Blank (Visual Effects Supervisor), this was the most expensive shot in the series — at least until Blank stepped down in Season 3. It's not just the meteorite's impact that's fun to watch, it's the post-apocalyptic imagery after the fact.
Minor-yet-cool effects: Hurley appearing in a mirror shard as Charlie shaves his beard, Roger Linus' corpse.
Really bad editing: the van's descent toward the rocks. This was something straight out of a cartoon, where the distant threat repeatedly "resets" to fifty feet away even though the van should've been smashed a good ten seconds before Hurley yanked the wheel. If this weren't such a memorable moment in the series I'd shrug it off, but it's so obvious it deserves a big 'ole deduction.
The directing in the "victory lap" scene is extremely good, taking us inside the van as Sawyer, Jin, and Vincent all run up to join the fun. No word on whether Vincent stuck his nose out the window while the ride was in progress.
The excellent directing and editing carries right into an emotional montage, slow-mos of the characters returning to the beach camp while Hurley stays behind in the van. It's one of my favorite moments in the series.

The risk with comedic episodes is that I need to be in the right frame of mind, but for some reason TTiD always entertains me. The moment Vincent runs up to Hurley and Charlie with a skeletal arm in his mouth I know I'm in for a real treat.
So yeah... give me TTiD any day of the week and I'll enjoy it all the same.
The episode's significance is debatable as some fans seem determined to slap it with the "filler" label. I'm not sure I understand the reasoning, for it's just as important to see Hurley tackling his daddy issues as any other character. Granted, the mythology wasn't advanced all that much beyond the introduction of Roger Linus, but I certainly don't think TTiD was an example of stalling in any way, shape, or form.
It was especially significant in terms of making me genuinely care about Hurley's family situation for the first time.

Atmosphere isn't exactly the goal of a comedic episode, but the "victory lap" scene certainly does have an atmosphere all its own. For just a moment that scene makes the island feel like a home away from home.
Emotional impact: another thing that's generally not associated with a comedy-driven episode. And yet that's the real beauty of TTiD, after 30+ minutes of hilarity it suddenly turns very personal. You don't need to have your own daddy issues to acknowledge and appreciate what Hurley's just been through, how vital it was for him to succeed.