With just the CGI films, this is how I rank it;
1. AATC 4: The Road Chip
2. AATC 1
3. AATC 2: The Squeakquel
4. AATC 3: Chipwreaked
Now, I love all of them, but Road Chip stood out the most for me. I still like the other three films, but as I stated, Road Chip is my favorite. Although, Chipwreaked does have the best soundtrack out of all the other films, in my opinion.
I enjoyed all the live action/CGI films very much, and so it took me a while to rank all of them. Now, I like them, from least favorite to absolute favorite, in the order of which they came, so here is my ranking:
1. Alvin and the Chipmunks, with 7/10
2. Alvin and the Chipmunks: The Squeakquel, with 8/10
3. Alvin and the Chipmunks: Chipwrecked, with 8.5/10
4. Alvin and the Chipmunks: The Road Chip, with 9/10
Road Chip is definitely my favorite. I also say this on the thread in which everyone posted their reviews for The Road Chip.