Jiraiya first battle: Invasion fo Konoha we see the Konoha shinobi having great trouble with two giant snakes, yet Jiraiya defeats the snakes easily with a single jutsu.
Jiraiya vs Orochimaru (sannin fight)
As stated before Jiraiya and Orochimaru had a handicap, yet Jiraiya was capable of making an enourmous swamp sinking orochimaru's snakes and capable of defending himself wuite well even though he was drugged.
Jiraiya vs Naruto (4 tails?)
We didn't se what happend but Jiraiya was greatly injured, but i imagine he was not ready for that amount of power, also he did not try to kill naruto so i believe if he knew that amount of power the 4 tails had he would have easily avoided it.
Jiraiya vs Itachi (staredown) Jiraiya using only one jutsu to trap Itachi and Kisame, having trouble defending themselves where jiraiya say no one has ever escaped this jutsu. Now many say Itachi didn't want to hurt Jiraiya since he was a Konoha shinobi, (i partly agree) since there could be many more reasons behind, such as he had already used Tsukuyomi twice and Amaterasu to get out of Jiraiya's technique.
Jiraiya vs Konan, this battle is insignificant, since i believe it is just a bad matchup since Jiraiya's oil can easily counter Konan's moves.
Jiraiya vs Pein: Now this is the greatest battle we have seen from Jiraiya... Also his final battle

Jiraiya had no trouble at all getting time to enter SM, by summoning Gamaken and using a barrier defense and Shadow Clones, he was able to avoid and counter (was it 4 summons or 5 idk) he actually only really had trouble with the dog summon with more heads, but in the end it looked like he didn't really have any trouble countering the summons. Now after Jiraiya enters SM, we see many new jutsu such as his Goemon jutsu which would probably have reduced Pein to cinders if his paths didn't have those specific defenses. Also he had a one hit K.O on one pein but it was revived, he only hit it once in the head. Now he fought quite well and used Oodoma rasengan but with no use because of Pein's annoying defense.
Now for Jiraiya's easy way out was Genjutsu with Ma & Pa, he killed 3 peins that way and actually he killed one pein twice. Alright afer the genjutsu was over he let his guard down believing the battle was over. That's the reason he died, though if he had kept up his guard and maybe knew about his secret he could have done so much more, maybe even come up against the strongest pein... (maybe even winning, not sure)