Here is my list of the best first sequel movies.

1. The Lord of the Rings: The Two Towers (2002) - Best fantasy series ever made
2. Aliens (1986) - Expanded Alien into an entire universe
3. Star Trek II: The Wrath of Khan (1982) - Khaaaan!
4. Terminator 2: Judgment Day (1991) - He came back
5. Star Wars Episode V: The Empire Strikes Back (1980) - Was the second movie made of the series before all that prequel junk
6. Hellboy II: The Golden Army (2008) - Great creature designs
7. Predator 2 (1990) - Glover on the Predator ship was my favorite scene
8. The Mummy Returns (2001) - Two reasons: Rachel Weisz & Patricia Velásquez
9. Mad Max 2: The Road Warrior (1981) - would anyone remembered "Mad Max" if it wasn't for this movie?
10. From Russia with Love - Still my favorite Bond movie