The MOST important thing to burn DVDs for PS2 is to make sure that the burning is done at
constant speed.
I use nero7 (even nero6) to burn my DVDs (
smartbuy DVD+RW 1-4X [Prodisc]) but nero doesn't tell you the actual speed with which you're burning (like Alcohol) so the
best choice is to select the lowest speed supported by you burner and media (in my case 2.4x).
This is because probably there aren't any DVD burners that write at max speed from the begining of the burning process. For e.g. an 8x DVD Writer starts with 4x for the first ~30% than 6x for the next ~40% and the rest will burn it at 8x (numbers are very approx.). This will create problems (choppy/lagged) if you're you're using the PS2 (mine is big not modded & 4 years old) to play them but not on a PC DVD-Drive.
Hope that I helped you.
PS. I use DVD+RW because I store the backed-up movies as small avi files and not DVDs so that I can fit ~6 movies on a DVD-R (economical huh 
).