From personal experience these are the ones that stood out:
Chris Jericho - Met him a few times and is a good guy to chat with, providing you don't do something to irritate him.
Paul Bearer - Met him at Axxess for WM28, he was such a genuinely nice guy. Always pleasant to the fans and having a smile on his face, you can tell he's someone who truly loved the business through and through.
Mick Foley - Given he's been doing things for charity long before Cena came, you can tell he's a caring person, especially about children. But such a pleasant guy and knows how to have fun. He's the guy you'd want for an uncle.
JR/Lawler - This is based from Axxess where a number of us were queuing for 2 hours to see them, and it was getting close to closing for the day. Staff were telling us to leave and people were getting pissed. JR & King then told people to get whatever items they wanted signed ready, came down from their table and signed all the fan's items. The fact they did that was a really nice thing for them to do.
Lita - Again, another individual who's really pleasant to the fans.
Kane - I remember marking out so badly when I got to meet him that I remember spewing out random stuff about how I just was so glad to win the title back in 2010 and he was very humbled by it and appreciated the support.
Met Big Show and Dave said to him "You've got big hands" to which he replied "I'd look kinda silly with small hands".
That was a good day. I remember just being frozen from seeing how big his hands were. Wasn't it Tasty who suggested getting a CM Punk figure for him to sign?