My pick would be Jun Akiyama in all white. It just makes him stand out and isn't super elaborate or anything.

I also like BUSHI coming out with 43 masks on top of each other for his ringwalk. Other LIJ members have too much stuff going but it works for BUSHI imo. Rush's ringwalk mask is also really cool.

Took me a minute to think of some others because I went for Shinzaki/Hakushi right off the bat and then to Sabu & Hayabusa

Akiyama in white is a good pick. It was slight change overall but, made a big difference in his shift in character in NOAH. The fact that he switched back to blue after he lost the belt in '06 was a nice touch.

Mariko Yoshida I second as well. Like Jun, it clearly signified a change from her younger days.

With Joshi in mind, I'm going to say Akira Hokuto's Kabuki mask, robes, & katana entrance attire always gave me goosebumps. Similarly, Bull Nakano in her robes and spiked long blue hair reminded me of an ice queen or someone of legend. 

Also, I'm going to say Taz  with the beat up towel over his face, black singlet, and shooter boots. It was a simple look but, it really got his intense tough guy look over. That being said, I didn't care for the Team Taz era stuff though. That was corny to me.

Finally, Papa Shango because that was the height of cool wrestling look to me as a kid. Skull face paint!