Suggestion for graphics card

[Subinkumar]

intel pentium dual core e5200 2.5GHz,2gb ram,1TB hard disk,400W psu,PCI express slot.Suggest me some graphics card for this specification?? and how cold i know pci express 2.0 or 3.0 and x16 ??

 

[RobCrezz]

gtx 750

 

[WarWolverineWarrior]

RX 550