Also, remember, you may not have to spend any money at all.
Depending on your level of PC knowledge, do you:-
Have a PC hooked up to your PS3?
You could rip your DVDs to your PC HDD as one big .mpg file (so no loss of quality) and stream to your PS3. No need to burn anything.
Or, rip the DVD to your PC, and use a free XviD encoder to covert it to XviD. No need to skimp on the quality like some dubious internet releases. Manually set the res, and filesize to 1.99gb (to avoid file system restrictions) and then stick the file on a USB key, or other method to copy to the PS3 HDD and play back.
There are softwares available, which I guess I'd better not mention in here, but Slysoft do one, that will rip a DVD to your HDD and encode it to h.264 .mp4 files, which could also be played back from a usb key/PS3 hdd.
Lots of other methods of watching your films on your PS3/TV, without having to spend money
Remember though, if you spend £100+ on an upscaling DVD player, HDMI switch etc, chances are, the upscaler wouldn't give the same quality as the PS3 DVD player. I've seen about 7 upscaling DVD players personally, connected to the same TV as a PS3, and the PS3 beat all of them, easily.
Vin.