Naruto and Sasuke are obvious
Sakura- Doton: magnify her ground punches to extreme levels. Also, can create walls to block and walls as platform launchers for rushing.
Shikamaru- Doton: control of the earth grants access to a ton of shadow options...creating tunnels, walls, etc..would produce extended shadows. Alternate- Katon: burning shadows sounds cool, but also he could manipulate the shadows made by fire...also has the Will of Fire.
Choji- Fuuton: While you didn't like it, I think it works as it could mix with Butterfly mode. Also, the could create a dangerous spiked human boulder, and wind techniques from his enlarged body would be large scale!
Ino- Raiton: Since she isn't much of a combatant, having a charge on that kunai helps. In addition, once can theorize control of electricity could include the electrical currents of the nervous system allowing for quicker, larger, and more efficient mind controls.
Neji- Raiton: using the palm techniques would stun on impact. Air Palm and Rotation add shock damage.
Lee- Katon: Matches his burning passion....useless since he has no ninjutsu talent.
Tenten- Raiton: Shock damage on weapons.
Kiba- Katon: Flamming Gatsuga or Tail Whirlwind sounds good to me. Validates Akamaru's Red namesake.
Shino- Doton: Manipulating earth grants him more mobility and versatility for insects. Also, it probably provides a wide variety of insects to manipulate.
Hinata- Suiton: Firstly it seems to match her as a gentle calm current could reflect her personality. Anyhow, She could use it in some of the ways the anime showed with her water bullets, and maybe and upgrade to her anime Guardian 64 Palms. Additionally she could probably manipulate it similarly to Water Benders in Avatar since the Hyuga have good chakra control. Finally, she could use it as a mobility increase. Similarly to Tobirama in Storm Generations, she could use it to glide on the ground, and spin as a way to hit multiple foes with Twin Lion Fists/64 palms if she were using it. I suppose it would also be similar to Fisherman Karate when it comes to Air Palm (One Piece: manipulates the water within a person to cause damage), and also when striking chakra points could be used to manipulate water in one's body.