I would like to upgrade my Dell Dimension 2400 desktop and get a CD RW/DVD combo drive (just have CD rom now).  However with Intel Celeron 2.4 ghz processor not sure if anything is compatible, looks like you need a Pentium at the minimum.
I did upgrade the memory to 768 MB recently.  I have W XP Home SP2.
 
Primary use will be data and photos and viewing movies, nothing real complicated and I'm hoping not to spend a lot to do this, but want something that is dependable.
 
Any recommendation on brands and what I can do with my current system?
Thanks for any advice.

take your pick, they will work for ya..
 
also think about this.. for a few bucks more, you can probably go dvdrw too.

Generally you may as well get a DVD burner(i assume you mean that anyway) since it will read and write to both CD's and DVD's
 
Since your system is a little older, the drive should be IDE and NOT sata.
 
Most drives tend to work more or less the same. Some would say plextor is the best(they are damn good), but with price as a concern just get what ever is cheap.

It is better to use CD-R/W+DVD-ROM(COMBO)  without any brand,  it compatible with all PCs, then you can not think over it any more.

From combo drives i have used so far , creative and sony drives are durable and have better performance than my samsung drive which is quieter than the other two . But samsung drive had various kinds of problems. So i avoid samsung optical drives.