There are three incarnations of the fantasy tradition of half-sized humans that come to my mind when I think about halflings. I admit there are more than that worth considering, but my knowledge and experience is limited. For instance, the halflings of Athas in Dead Sun are savage and cannibalistic jungle dwellers. That's pretty unique, but I have basically no experience with them myself, so they don't figure into my musings except as interesting edge cases.
There's no getting around the primary source of the trope. The Tolkien estate apparently guards the term and tradition of "hobbit" with great diligence, and it's that ever-present legal threat that gave rise to the term "halfling". Far from becoming a sad off-brand version of its famous sibling, the word "halfling" managed to engulfed the term "hobbit", becoming the generic superset. After all, were you to refer to a hobbit as a "halfling" in conversation with even an ardent Tolkien fan, they would know what you meant, and they probably wouldn't bat an eye at the turn of phrase. It's descriptive and familiar, and only a fellow D&D nerd would think to ask "what kind?"
In this case, the kind I mean is the hobbit kind. I grew up with hobbits and their lazy, isolated, simple but luxurious culture, and later in life I was lucky enough to have worked on the movies featuring them, and to visit Hobbiton, and so on. If nothing else, they serve as a good baseline for what you assume a halfling, in the generic sense, would be like.
Hobbit variants pop up in Willow, the Forgotten Realms, and in countless fantasy dime novels. Hobbits and hobbit-likes are a safe, middle-of-the-road, and notably the original, implementation of the concept.
After Narnia and Middle Earth, the other fantasy world of my youth was Dragonlance. The Kinder are, for me, the quintessential D&D halflings. I don't actually use the standard Forgotten Realms halfling in games. It's not exactly intentional or even a conscious choice, I just default to Kinder, whether as a PC or NPC. Their literal lack of fear or concept of ownership, their innate cheerfulness and luck, and their insatiable wanderlust, are all things I identify with and admire.
These are easily my favourite implementation, even above Hobbits and Hobbit-likes. In a way, I guess Kinders are the embodiment of the Hobbits you fall in love with from the books and movies. You don't get excited about Bilbo or Frodo because they sit at home and smoke and garden, because that's not what they do. You fall in love with them because they go out, explore, burgle, and brave impossible odds. They're atypical hobbits. They're more akin to Kinder than Hobbit.
I never meant to be drawn to the halflings of Pathfinder's Golarion. It's easy to overlook them, in fact, because when you encounter them in most situations, they seems mostly like standard generic fantasy Hobbit-likes. They're jovial, they wander the world in search of adventure, they have funny names, they're naturally lucky. All the usual tropes apply. But ask a Golarion halfling about their family history, and you might be in for a shock.
Canonically, the halflings of Golarion were actually a severely oppressed race. For much of their history, halflings were enslaved by the ancient Osirians. A branch of that population escaped to Katapesh, but after ancient Osirion collapsed many were enslaved again by Taldor, which continues in modern day Cheliax. Halflings on Golarion are a people without a know homeland. The don't know their own origins, so their wanderlust is only partly borne of curiousity and adventure.
It's difficult to call the tale of historical enslavement and oppression "inspiring", but that is part of the effect that the history of halflings has in Pathfinder. I find their story sad and painful to read, but then again halflings persist. They carry on, bringing their skills and mischief and uncanny luck and cheerful faces to the whole planet of Golarion.
Unlike hobbits and kinders, the halflings of Golarion haven't been part of my mental fantasy codex since childhood. They were relatively recent discoveries, but when you read their backstory it's not something you forget. They're a unique, and yet familiar, take on the halfling tradition, and it's one that I think suits the little race well.
Halflings are a fun race to play in an RPG. If you tend to overlook them as just-smaller-humans then you ought to give them a second look. Depending on your setting, there may be a lot more to them than you at first realize, so delve into some lore and discover something new about halflings.
Photo by Mixed Signals. Creative Commons cc0.