What’s the best consumer level FPGA that I can buy to experiment with? One that has the highest speed of final product and most memory etc? What’s the best of the best?
Zynq 7000 family is a more affordable entry point, but resources are more limited in every regard, and uses a slower, more power consuming process.
Lattice-based boards are great because they are supported by open source tooling, and available in many indie buildouts (ECP5 or or ice). They are not so high end though, by far, compared to Xilinx parts.
Intel (ex-Altera) seems to have good stuff, but not as advanced as Xilinx. They are used on the mist and mister systems for hardware retro game emulation, a quite active scene.
I like the lattice stuff for experimenting because you can do the whole stack with free software.
They are cheap and are supported by the FOSS toolchain. So you won't waste money or wrestle with crappy and/or expensive commercial tools, and can concentrate on learning FPGA.
Neither of these have high speed serial interfaces (for things like ethernet, PCIe, HDMI, etc.), but they're fun starting points.
I'd love to get into making my own FPGA boards, but man, BGAs are scary from a hobbyist perspective. The Spartan 6 LX9 is neat (from a hobbyist perspective) in that it's a big QFP.
If you’re just wanting to learn and experiment, like myself, then Digilent makes a lot of nicely packaged boards. The Nexys A7 is a capable board.