Terminator 2 was, and still is, the greatest movie sequel ever made (yes, including The Empire Strikes Back and the Two Towers). It takes everything that was great about the first movie and dials it up to 11 while also expanding the lore AND delving deeper into the characters. Just think about Sarah Connor's character in this movie, compared to the first one. She went from being, essentially, a damsel in distress to a full-on badass, While also suffering the mental repercussions from the events of the first movie. Even the friggin' Terminator gets a character arc in this movie!
Now let's talk about the visual effects in the sequel, which not only surpassed the effects in the first one, they actually changed the entire industry. The program they developed to make the T-1000 morph into different characters actually went on to become the first version of Photoshop. If you have never seen Terminator 2 - Drop everything you're doing and go see it now!