I chose 3.
The incinerator scene was just… wow… the toys finally realized that no matter what they could do, they were going to be destroyed. So much conveyed in a few seconds. No more Andy, no more playtime, nothing else is going to come next. Just … the end.
I thought it was great. Toy mortality.
Love them all, but 2 gets my vote as the funniest and most emotional.
I love the Zurg framing story/shoutouts to Star Wars, as well as the Woody’s Roundup show-within-a-show.
I choose 2, for all the reasons 2-supporters listed above, plus it has the best villain and the best comeuppance for that villain, in my opinion.
She’s an artist!
I’m an outlier- I saw the original and didn’t like it at all. I thought Pixar was highly overrated for quite some time.
I wasn’t hooked until Finding Nemo. Subsequently, I loved ***Toy Story 2 ***and REALLY loved Toy Story 3.
I must say, however, with some sadness… I’ve liked recent Pixar efforts, but haven’t LOVED a Pixar movie in a few years now.
Yep, Pixar’s certainly dropped in quality. And it’s easy to pin-point the exact moment: Cars. While they’ve since made much better films, none of them rank with the overall excellence of their first 10 years.
Yeah, it’s Dan Whitney’s fault.
LET’S GET HIM!
(I hate that character so much that I call him “Tomato,” just to be ornery.)
I dissent from that “none of them” bit, and cite Ratatouille, Up, and I’ll let someone else make the case for WALL-E (although I’m willing to be persuaded).
Does anyone know if Michael Crawford got compensated for his performance in WALL-E?
toy story came out when i was 14, and i remember enjoying it, but it didn’t change my life or anything.
toy story 2 came out when i was 18, which was, at least for me, that phase where you’re too old to be interested in those kinds of movies. i’ve never even seen the whole thing (although i have seen the “when she loved me” sequence and it never fails to make me cry.)
toy story 3 came out when i was 29, and i was profoundly moved by it. i’m not sure if it was intended this way(probably not), but how the movies were spaced out really ended up being a stroke of brilliance for the franchise. by the time those of us who were kids when the first movie came out saw the third film, we’d learned a thing or two about loss and growing up and learning to let go of our childhoods, and the theme of the film really resonates. it works for other generations, too-parents who took their young kids to see part one were facing similar scenarios as andy’s mom and the toys by the time part three rolled around. i’ve never gotten through a viewing without being moved to tears.
also, it seems almost unfair to the first two films to say three has the best animation, but the animation really is sharp. i can’t take my eyes off of Lotso whenever he’s onscreen-he just looks incredible. the spanish Buzz stuff always makes me laugh, and i really like the dark feel of the whole movie. three is my pick, in case it’s not obvious. 
Wall-e was half a good movie, but that second half…christ. Ratatouille was deeply flawed imo, but wasn’t terribly. I will concede Up is probably the closest they’ve come to classic Pixar.
I personally voted for 2 because while I think all three are great, 2 was the best for character development. In the first and third movies, the characters were primarily reacted to events beyond their control: Buzz’s arrival, being lost at Pizza Planet, being trapped at Sid’s, being put into storage, being accidentally thrown out, being betrayed by Lotso. But in the second movie, there’s a real choice: Woody can go to Japan or back to Andy. When he goes back to Andy in this movie it wasn’t just because he was trying to escape from something.
It’s really hard for me to choose. I was a full blown adult when I saw each of them. I liked the outtakes and bloopers from 2 the most. Especially when Stinky Pete was putting the moves on TWO Barbies.
Uh, well, I’m an outlier again, on the SDMB anyway. I LIKED Cars. A lot. And it was my son’s favorite Pixar movie.
Cars 2 absolutely bit the big one, however.
I’m a double outlier. I put Cars among Pixar’s best and am mystified by the endless adoration of Nemo - which was good, no question, but not that good.
Cars was probably good if you’re a motorhead, but it doesn’t have the breadth that most Pixar movies do. For us non-motorheads, there’s really not much that appeals.
And I also rate Finding Nemo relatively low, for a Pixar movie. I’ve a hunch that most of the people who love it are parents, for whom it resonates more.
Personally, I think the best Pixar movie is The Incredibles, which works really well in many different ways at once. It’s a great superhero movie, it’s a great spy thriller, it’s a great movie about a perfectly ordinary family and their perfectly ordinary problems.
Legally and chronologically, I was a full-grown adult when I saw all three movies. Not mentally, mind you, nor emotionally. But I play an adult at work. 
I concur. “Toy Story” was just so different, brilliant in its creation of this entire toy universe, that I felt its impact immediately. The next two built upon that world in their own brilliant way. And I saw the first one at The Egyptian theater in Hollywood with life-size toy soldiers trying to walk while stuck on rigid bases, do-it-yourself Toy Story themed Lite Brites. Good times!