Scythe Gentle Typhoons, best case fan i have ever used. After running some tests on the models that are similar the noctua and GT are almost spot on the same. The gentle typhoon make more of a woosh noise (if you can actually call it noise) where as the noctua sound more like ambient noise cutting in the background. Seeing as both of these are really not noticable unless you sit next to your case and listen I would pick either one of these. But I just cant stomach the noctua color scheme. I dont actually find the color too bad when the fan is alone. But when I take the jet black and white interior of my case and put noctuas against it I die a little.
Both are comparable in price, the GT's have a few more srock rpm options then noctua does.
I once made the mistake of fitting out my old kandalf with Delta fans. When i first hit that power button me and my girlfriend dived behined the Sofa. we thought a harrier jump jet was landing int he living room.
Deltas are more suitable to a hovercraft than a pc so cross them off your list lol.
But latly after seing a oc3d build on youtube i went and got some Phobya fans. absolutly stunning looking, and near as damit silent. with a nice rush of cool air. very very nice fans.