I fucking love Battle Royale and have watched it on an average of once a month since I bought it.
It's a great film, with Kiriyama being my favourite character. I pretty much love anything with Takeshi Kitano in it (Takeshi not wanting to share the cookies is a great, subtle comedy moment), and having about 20 really cute Japanese girls in school uniforms doesn't hurt. My favourite bit is Kiriyama putting the megaphone to the dying girl so everyone can hear her squeal before he just tears her apart with the machine gun. The scene with the 6 girls in the kitchen trying to poison the guy sleeping upstairs is classic, I love when things break down to utter madness that quickly. Also really liked the soundtrack, especially the dream themes and ending theme.
I know a lot of people have a hard on for hating #2 and it certainly does have a lot of flaws, and gets a bit preachy....well really preachy, but it also has a lot of good moments in it although the kids got killed off way too fast and impersonal so you never really cared about most of them.