You jelly.

The thing is with the TV series, many recommend to watch it up until episode 25, stop there, and watch End of Evangelion. This is because people go bats'hit crazy trying to understand what episode 25 and 26 are really about and to this day no one really knows. (Lul many years later). What happened was Hideaki Anno took a turn in the middle of the anime as he started reading books about Psychology and thus he wanted to incorporate these aspects into the anime. He wanted to expose things to the children he knew were watching this so they wouldn't grow up misguide, etc. etc. Towards the end, many things led to the confusing last two episodes, one mainly being they were rushed for time in making them and releasing them. Another was they were low on money due to tax problems. And another was Anno was going through critical depression.

So with that, the series ended and fans were so pissed they started sending him death threats through e-mail and mail, and eventually vandalizing the Gainax studios. So he pretty much mocked the community and said "Okay, if you want me to ruin the ending then I will, here you guys go. This is what was really happening. Here's your ending. This is what you guys wanted, right?" (Not really, but pretty much what was intended). And therefore, the End of Evangelion was produced which is a re-telling of strictly the last two episodes of the series.

The other movies, such as Death and Rebirth are re-tellings of the whole series just with more content (kind of unnecessary but still good watches ^^). And now he and his own studio are developing a "Rebuild" of the series where they are re-mastered, much more content added, and even new characters. All of them are worth watching, but primarily the series, EoE, and the rebuilds.

Warning End of Evangelion is batshit insane and will cause you to make you question yourself when you see the Asuka and Shinji in the hospital part.

Also to help with the confusion you will have:

 Spoiler

Human A.T. fields are what constrains a soul to their respective body. Without it your body liquifies and your soul is set free. An anti A.T. field seems to be just a large explosion which can destroy AT fields but only when the Third Impact happens. Without the Third Impact its just a big explosion (as we have seen when angels self-destruct). The Human Instrumentality Project is a plan conceived by SEELE (a bit like the G8 council but way more powerful) and they placed Ikari in-charge. It is where everybody's soul is detached from their body by making Ayanami Rei (a genetic modification of Lilith (the big white person in the Central Dogma)) enter Lilith (an angel from which humanity descends (all angels are supposedly alternate forms of mankind and would have taken one of these forms if evolution took a different turn)). This meeting of Ayanami and Lilith, called the Third Impact, will destroy everybody's AT but it also requires Eva Unit 01 to work as an amplifier or medium. Essentially SEELE wants everybody's souls to unite so that everybody is happy or whatever and by doing this they have reentered the garden of Eden. However Ikari wants to use Adam to initialize the Third Impact. I dont understand what happens if either Adam or Lilith is used but in the film they use both (remember Adam is the fetus in Ikari's hand). Adam blew himself up 15 years earlier in the Second Impact turning himself into a fertilized egg cell and this was inserted into Ikari's hand.