Okay I have started to notice some similarities between the episodes in season one and the episodes in season two so I am going to be writing down what I see. Small differences are in bold. I know you probably all know about those small differences but it feels weird to not state them when I am writing. (I haven't got to all of them yet and we are only four episodes into the second season so this blog will be updated)
Independence Day vs. Happy New Year- So the first thing is that they both take place on Holidays, July 4th and January 1st. Then we have a villain/s going on a rampage for no apparent reason. S2 we latter find out why in the same episode. (Ice villians and Lobo) After the fight those that have high security clearance have a debrief on the fight. S1 they try to but Speedy (Clone) interrupts. S2 we actually get to see the debrief. Then for the rest of the episode three underdogs ( S1sidekicks) go to a huge underground facility of a villain that has just been revealed.(S2 it's actually a mission) They kick but and save a hostage, in the process of escaping they bring the facility down on top of them. Then the entire Justice league shows up.
Happy Harbor vs. Earthilings- Superboy gets mad when Miss Martian uses her telepathic powers on other and him. S1 is when she doesn't mean to upset any one and apologises.
Drop Zone vs Alienated - The mission is set up to be primarily a recon mission. The investigation site is a small island with the first "drop zone" being for atlantians. A certain trait is revealed about Kaldur and he takes a new place among out heroes. Robin tries to hack into the computer. S2 it was just a small clip. In the final fight there is a lot of team work but the villain still escapes and sets the base up in smoke. S1 Sportsmaster didn't mean too.
That is it for now but I am almost done with the next one
Schooled vs. Savage So we start with a small crisis that a clone comes and fixes, how he does this however angers his "mentor" causing some bad feelings. The clone then goes up against Black Canary feeling confident and gets his butt kicked. In the main plot there is a very powerful enemy that isn't exactly destroyed by the team. S1 Wally would be dead without Artemis. In the end the clone accepts the help and in a round about way this is the episode in each season where we get to see Artemis.
Infiltrator vs. Bloodlines So the entire B plot of Bloodlines mirrors the first scene of Infiltrator with Red Arrow and Chesire breaking into a temple like headquarters of the shadows (S2 not confirmed) and freeing a prisoner. Then we get a new character introduced with a very hasty back story. Wally seems to dislike this character but puts up with them for the mission however when they make a mistake he is quick to yell, he is however shut down with an "that's not fair" by another member of his team/family. In the end member is accepted into the Team and all are happy. Ending scene however show us that this character was lying about some really big stuff in his/her back story. We the audience however aren't that worried. Then we get another scene that no one know about showing that something is going to go very wrong. S1 or just cause a lot of problems for our heroes.