I saw Cowboy Bebop: The Movie (2001).
You should watch it after watching Cowboy Bebop, the TV series, otherwise you won't know the main characters at all.
The TV series has only twenty episodes, and there is just one movie.
The TV series and the movie have excellent acting and music.
The writing is also superb.
All of it is originally in Japanese, but there are English dubbed versions, which is what I watched, and the English versions are amazing.
Out of all of the anime that I have seen, I like Cowboy Bebop the most.
If you've never gotten into anime, I would start with CB.
On to the movie.
The beginning of the movie has some sorta slow parts, but the last two thirds are golden.
Overall, I love the movie, just like I love the TV series.
I wish there was more CB to watch, and as a side note, I've always wanted a Corgi because of CB, and I have had Corgi since 2008.
The animation of the Corgi in CB is very accurate, and as it turns out Corgis are an excellent breed if you don't mind having a short dog.
You would really have to hate anime to not thoroughly enjoy Cowboy Bebop.