Playstation has better single-player exclusives, so since you'll be without internet, you might want to pickup a PS3 and a couple games like Uncharted, CoD, or Heavy Rain.
There is quite a few things to consider before picking a console. Especially with the money your paying for them nowadays. What type of games do you like? Would you prefer free online gaming over paying a buck? What other extras will you use more on whatever system you buy?
I voted for 360 myself, because if it's for gaming, I feel that the Xbox has a better variety then the PS3(This is strictly my opinion!). Plus no backwards compatibility anymore(You can still play ps1 games though!) really lowers it for me as well but you get a Blue-ray player, which is freaking sweet.
You have to think about what you will yourself enjoy more, I know which one I play more since I had both. A tip though, don't put your credit card on either systems! Neither is safe man...
360, I had one forever it finally broke after 5 years so got a PS3. I am regretting it, PS3 just lacks a lot of games the 360 has unfortunately. And even if your using it as mediabox the 360 is better since the PS3 enforces the stupid Cinavia protection on media.