one is a Toshiba Satellite L55T-A, it has the newer i7-4700 Processor, but only 8 GB of RAM. It also doesn't have a backlit keyboard, something i could live without, but it would be nice. It has Mobile Intel HD Graphics with 32MB-1632MB. integrated Graphics.
the other one is a Toshiba Satellite S55T series, it has an older i7 3630 processor, but 12GB of RAM. This one does have a backlit keyboard. This has Mobile Intel® HM76 Express Chipset Mobile Intel® HD graphics with shared graphics. Discrete Graphics.
Which one of these two would be better? The first one is a little cheaper, but i heard that the S series laptops are faster than the L series.
What are the graphics cards on them? Do they have other Nvidia or ATI cards installed? Right now I'd be leaning towards the L55T-A right now, as it has a stronger processor and you shouldn't need 12gb of RAM. Depending on the graphics card though that may change.
I think the "Discrete Graphics" Means that the S55T has a secondary graphics card and will usually perform better in games and at playing higher quality videos. It depends on the graphics chip installed as to how much better though.