T e a c h e r s

Iruka
Naruto's old teacher at the academy seems to have some difficulties with Kakashi. Iruka has protested against Kakashi a few times because of his judgement with his old students. When Iruka tried to argue that Naruto and his teammates were too young to start the chunnin exam, Kakashi reprimanded him that they weren't Iruka's students anymore, they were his. But Iruka does acknowledge Kakashi as a good teacher.
 
Sarutobi Asuma
Asuma's the teacher for Ino's team...there really isn't very much friction between Kakashi and him other than just simple rivalry between students. Asuma seems a little too laid back (probably even more so than Kakashi 0_o;;) to really take their rivalry anything farther beyond friendly.
 

Yuuhi Kurenai
Kurenai's the teacher for Hinata's team. Even though she's female, she's the newest addition to the Jounin group. She respects Kakashi a great deal and refers to him as "Kakashi-senpai" (senpai=a term used for respected upperclassmen). Kakashi did however tease her a bit when he caught Asuma and her together, asking if they were on a date...something between these two...who knows?
 

Gai
He considers Kakashi his ultimate rival, but he considers himself superior to Kakashi...he even kept count of the score who won in their battles (according to Gai, it's a score from 50 to 49). Kakashi hasn't agreed or denied that Gai won against him. Actually, Kakashi seems indifferent to Gai's rants, if anything. Possibly the one thing Kakashi does admire about Gai is that his student is the genius Rock Lee.
 
Morino Ibiki
Captain of the Leaf Village interrogation (aka, torture) team, Ibiki is the instructor for the first chunnin exam. Kakashi (as well as many other jounins), consider him a sadist. Kakashi silently pities his students for being under his supervision because of that fact. But Kakashi also acknowledges Ibiki in not only having skills of torturing physically, but also mentally.
 
Mitarashi Anko
Another female jounin, she is the instructor for the 2nd chunnin exam. Anko and Kakashi have nothing but mutual respect for one another. It was actually Anko that told Iruka that she was expecting to be impressed with Naruto's team because they are Kakashi's students. (I should also note, Sakura called Anko "Naruto-like" ^^). Anko was one of Orochimaru's henchmen, so she should be around Kakashi's level.
 
3rd Hokage
The Hokage is the strongest ninja and also the leader of Leaf Village. He has as much respect for Kakashi as Kakashi does for him. Both Hokage and Kakashi seem to have the same thought pattern when it's regarding Naruto. However, Hokage does find Kakashi a bit too strict with his students since he never passed any student before Naruto and his team, but Hokage still stands by his decisions none the less.