GW2 is dependent on the CPU, so it’s the key component to increasing performance. Since GW2 is using DX9, it’s also limited by the performance of a single core, so a CPU with a high single thread performance is going to be better than an 8+ core CPU with a lower single thread performance but higher multi thread performance. Intel i7-4790K for example.
For the GPU, you’ll only see very minimal gains the better you go, but stick with NVidia. GTX 770+, 970+, 1070+, whatever. You’ll want to look at other games you play, or plan to in the future, to determine how powerful of a card you want.
For RAM, GW2 64bit can easily use 6 GB, so you’ll want 8 GB at an absolute minimum. If you want to have some fun, go with 64 GB and load GW2 entirely into memory using RAM Disk software. If not, you’ll want an SSD to put GW2 on, because a slow load speed can cause stuttering.
