I have a Dell Inspiron 530s series with 3 GB of RAM 500 GB of memory space with an Intel Core Duo 2.4GHz processor and a Intel(R) G33/G31 Express Chipset Family it has a 250 watt power supply and is a slim tower. I was wondering the best graphics card upgrades so i could play some current games that require better cards
Probably your best bet considering you can only use a low profile card, and that dell has a weak power supply.
It is a pretty popular upgrade at the Dell forum and has slightly lower power consumption than the HD3450 that is offered in the machine.
Weak power supply is kinda relative to the machine, it was never intended to be a gamer.