MatheusroXWhat does "best" mean to you? The DAC80 is $300, the Marantz $800. The Marantz includes a headphone jack and an analog input. Do you need those features for $500. They use different chipsets, so they probably sound different. The CS4398 chipset has been used by Marantz for years in their equipment. The AKM 4390 used in the NuForce is also an older unit; do you need the latest whiz-bang ,processors. Do you really believe that newer always means better; do you still enjoy your 3-D TV, or have you ditched those annoying glasses? For $300, the NuForce is an excellent value; the market is flooded with $800 DACs. I would look at the Audeze Deckard first.
MatheusroXAs @gkrr commented these two are different products. Adding to the recommendations list, I would suggest you look at Matrix m-stage hpa-3u+ which is similar to Audeze in construction. I have to admit I haven't heard Audeze; so can't comment on how similar they sound, but I love my Matrix dac/amp.