FPGAs virtex sparton and kintex

what are the main differences between xilinx FPGAs virtex sparton and kintex
are there other families ?
and how to choose board"which copany produce the best boards"

spartan3 -- low cost FPGA, old now. Notable for the spartan3-an, which included on-die non-volative flash to retain programming. (other devices can use external flash for programming)
spartan6 -- low cost FPGA. spartan6 is more modern and much improved. (has LUT6's)
artix7 -- newest version of spartan (low-cost/low-power)
virtex2 -- old FPGA. Many research papers used the V2pro.
virtex4 -- introduced DSP48 resources. Some models also had a PPC microprocesor.
virtex5 -- introduced LUT6s and was a dramatic improvement over virtex4. Last of the virtex line to have a PPC option.
virtex6 -- improvement over the virtex5. Several minor improvements. Noteable for the lack of 3.3V capable IO. (artix7/kintex7/virtex7 have 3.3V IO)
kintex7 -- mid-level FPGA. something of a "virtex6.5" with performance and resources slightly better than the virtex6.
virtex7 -- current high-end FPGA.
zynq -- artix or kintex that includes a dual-ARM processor.