Which card shoud i get HD 3870 or 8800 GT both are PCie 2 but my mobo is PCi e 1.1?

Question

will it be a good idea to get a PCi2 on pCIe1.1 or shall just just tick with 2900XT or 8800GTS ....

Answer 1

Get the 8800 GT.
Don't worry, both the cards are backward compatible, so it will work perfectly on PCI-E 1.1

For the 8800 GT, get this one:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125081
It is as cheap as the standard 8800 GT, but it has a MUCH better cooler, and is overclocked 100 Mhz above the standard 8800 GT. It is a deal that you can't miss.