When I first played D&D 3.5, it was very exciting to me that not only could I be a charming, fleet-footed elf, but that I had dozens of choices for what kind of elf I could be. After quite a bit of waffling between the dozens of possibilities, I ended up backing down and going with a half-elf despite the low-crunch benefits of it. I just couldn't get enough meaningful background on any one elven race that separated it from every other one. Wood elves make sense, but what separates them thematically from wild elves? Aquatic elves sound awesome, but I will likely be on land most of the time anyway. What on earth is a grey elf? At least as a half-elf the confusion about the finer points of elven life could be in character.
This original battle with elven culture grew into a distinct dislike of the knife-earred archer-mages that until very recently has endured. I've now decided that in my games I will do away with the multitude of elven subraces and cut things down to three types of elves with a single stat block. If a player wishes to change the stat block I tend to be fairly flexible, but these are the three core variants that I allow. The elves are no longer just vaguely connected to the faerie, but thematically partially fae creatures. In a sense, the elven races are the continued lines of half-faerie.
The first step in recreating the elven races into something that works well for me was to completely remove the other elven subraces. While the previously existing sub-races may in some way be present within the revised elf that mostly falls upon the player to expand creatively rather than just setting down 'drow' and moving on. The starting place for elves at this point is just their base racial traits (from Pathfinder, 3.5 or whatever system you are using) and the lengthened lives. I don't hold by the essentially immortal concept, but they could certainly clock in a couple centuries with exercise and good eating.
Physically I think it is important to keep them at least partially recognizable as elves. I think that it is enough to keep them as generally slim with pointed ears. For the most part, they would be attractive, but it could certainly be a monstrous, dangerous beauty. In keeping with the faerie theme, there could be quite a bit of physical variation between what they look like, but that should be left up to DM/player discussion.
Every elven character will be connected to one of the two Faerie courts or will be a Wild Elf. This decision must be made at the beginning of play and should likely be a direct demonstration of their bloodline. Unseelie faeries have unseelie kids, seelie faeries have seelie kids. Wild elves could be handled slightly differently, perhaps as a conscious decision to try to fight for freedom from the courts. Thematically this connection is a responsibility and a boon available to the elves. Additionally at creation it may be a good idea to think of what kind of faerie your character is related to.
Seelie elves are descended from faeries of the seelie court. In keeping with their name as 'The Golden Ones' most seelie elves would be fair of skin with light colored hair. This is not, of course, to suggest that they all would be. There certainly could be a ruddier seelie elf. I like the idea of seelie elves having very green eyes.
Seelie elves have regular elven traits, but receive a +2 to relevant social checks with seelie faerie and a -2 to relevant social checks with unseelie faerie. Seelie faerie may bind a seelie elf to truth with a will-save dependent upon the strength of the faerie.
Unseelie elves are descended from faeries of the seelie court. Although the unseelie faerie are known for their mischief and oftentimes are malevolent, it shouldn't be assumed that every unseelie elf is evil. Indeed, it could be very fitting with a rakish rogue or bard to go with unseelie over seelie elf. Unseelie elves may vary physically as there is quite a bit of variation within the more individualistic unseelie court, but they are united with pale blue eyes.
Unseelie elves have regular elven traits, but receive a +2 to relevant social checks with unseelie faerie and a-2 to relevant social checks with seelie faerie. Unseelie faerie may bind an unseelie elf to truth with a will-save dependent upon the strength of the faerie.
Wyld elves are the elves descended from those faerie that are not properly on either side of the courts. They range in the middle because of pride, political strength, or just sheer animalistic tendencies. I picture these elves as taking more after the wood-elf of other games and having a kind of wild and unpredictable nature. Their eyes would be a space between green and blue to mark their lack of a court, though again their physical form could be influenced by their parents.
Wyld elves have regular elven traits and have a +1 to relevant social checks with wyld faeries and a -1 to relevant social checks with seelie or unseelie faeries. Wyld elves may make a verbal contract with a seelie or unseelie faerie in order to temporarily be treated as a seelie or unseelie elf. This contract ends at sunrise for unseelie contracts and sunset for seelie contracts.
But... But... I Want To Be Some Other Kind of Elf!
Well, the trick here is mostly discussion with the DM. If your dream is to be an aquatic elf, then talk with your DM and get naiad parents. If you want to be a wood-elf forest protector, you can easily fit into the Wyld elves. If you want to be a high-minded cultural elf, perhaps the Seelie Elves are for you. If you want to be a drow, then just be a malevolent unseelie elf. All of those subraces would exist as pretty much individual differences. The larger net for the type of elf brings in the plot hook of connection to the faerie and obligation to work for your court.