This article contains 4 applications for ripping DVDs on Linux: K9Copy, dvd::rip, acidrip and Thoggen.
K9Copy is a KDE application which allows ripping DVDs to many formats and it includes the possibility to rip to exact size (for example, rip a DVD into 2 files with 700 MB each). I wrote a full review here.
Currently at version 0.98.8, dvd::rip is a powerful tool built in GTK, with support for many video codecs, like Xvid, ffmpeg, or divx.
acidrip is yet another powerful graphical ripper built in GTK with many codecs available and the option to select the file size of the output.
Thoggen will generate Ogg Theora video files from your DVDs, having the option to rip ISO images or to access DVD data from a directory. You can also set the quality or size of the output video file.