In no particular order, the TVTropes that I love to read and write most;
Tear Jerker. I love a good tragedy, and this page helps me find plenty of reading material. Admittedly it's subjective, as some of the Tear Jerkers listed came across as gratuitous and over-the-top to me (see: Identity Crisis), but those of us who aren't afraid of a sad story can get a good idea of what they'll like.
Deconstruction: Tropes can be interpreted as rules, and when it comes to art, rules were meant to be broken. In a post-modern world, everything we know is driven by narrative, and if you're not actively taking it apart, you should ask yourself what you're doing.
Deconstructor Fleet: Most of my favorite stories of all time fall here.
Growing the Beard: The fact that series can do this is why I'm so drawn to serial fiction. While plenty of series run on longer than they should, and terrible sequels are practically the norm for many mediums, this is the strongest advantage of continuity.
Dysfunction Junction: Characters are more interesting when they're a complex mess, and the notion that ensemble casts need a token stable and happy character to balance out the more interesting characters is misguided. Everyone's some kind of mess, but that doesn't mean they can't be different kinds of screwed up.
Earn Your Happy Ending: To show that I'm not all about misery and ennui, I like it when all the character suffering and trauma actually results in something. If there's no ultimate gain to the protagonist's struggles, even if it doesn't occur within the protagonist's lifetime, then you run the risk of just being immature cynicism.
So Bad It's Horrible: You can learn just as much from complete failures as you can from a medium's canon, or even from its uneven but interesting entries. That, and they're fucking hilarious (albeit unintentionally).
Nakama: The one form of sentimentality that never fails for me is the kind that's earned through comraderie and shared experience. Religion, nationality, and ideology mean nothing without actual human relationships to back them up. Many of my favorite series run on this trope, and Ruby's World uses a similar structure.
ViewersAreGeniuses: Rare, and not always done well, but far better than the alternative.
Child Soldiers: In the real world, one of the worst examples of humanity's failings. In fiction, it appears a lot, and is often romanticized (see: most young adult fantasy stories). When played believably, mixing the horrors of war with the innocence of youth offers insight into the human condition, and how it can (and SHOULD) be bettered.