I don't know about others, but I had the best luck with AMSOils and Red Line. If you are gonna be going hardcore racing I would recommend Red Line, if you are using the car on daily basis AMSOil, in my opinion, is the best way to go.
Car - 2017 Civic Si
Engine Oil - Signature Series 0W-20 Synthetic Motor Oil
Oil filter - AMSOIL Ea Oil Filter
I agree with @Art123: I also use Amsoil. I've been buying the XL series oil as it's easily available near me and it's a bit cheaper than the Signature Series. I do my changes every 5,000 miles and I also do a tire rotation with each oil change. I've been using the OE Honda oil filters, and along with that I replace the intake air and cabin vent filters every third oil change (15,000 miles). I've found that this is a profoundly easy schedule to manage as every interval is consistent: 5, 10, 15, 20, 25, etc . . . The larger services are at 15, 30, 45, 60, etc.
For all of the other Hondas I've owned I've done a basic transmission service every 15,000 miles also (drain off (3) quarts of ATF and refill) as a part of my "Expanded Filter Service" interval. On many of the older Hondas this transmission service is pretty important (how many here had a 6th Gen Accord that puked its transmission well ahead of 100k miles?), so it's a habit I've gotten into, but I'm not sure whether this is so much a necessity with the CVT . . . Without as many clutch packs in there I'd hope that the fluid would stay cleaner longer, and for my wife's ILX it costs me about $30 to do the ATF service every 15k, so I suspect that the Civic will cost approximately the same.
Oh, and be warned: for those of us with the CVT there is yet another special lubrication requirement for this. It is Honda #08200-HCF2, and as with all other Honda non-manual transaxles it is advised that you do NOT deviate from the Honda branded fluid. Bernardi Honda actually has a nice little chart to show you what fluids should be used where on which model and year, and it includes hyperlinks to the pages for the fluids in question:
It also appears that there is some kind of a filter inside of the "CVT fluid warmer", Honda #25450-P4V-013, and there is also a strainer assembly in what appears to be the oil pan that probably needs to be replaced periodically (Honda #25420-5LJ-003). Neither of these parts are pricey from Honda (strainer is $16 retail, warmer filter is $19) and they should probably be considered.
Amsoil looks identical to the RP filter and very similar to Fram Utra, which is half price. If you're going to do extended oil changes, then Mobil 1 EP, Castrol EP, or Amsoil SS. If you're going with shorter OCIs, then just about any oil will do the job.
IT depends on what you're doing with the car. Brands don't matter that much, to be honest, I've been a part of MANY online oil discussions/fights/all out wars, and at the end of the day, after blackstone analyzes the oils, there is very little difference except when it comes to synthetic vs conventional and the different oil weights.
Honda recommends 0w-20, and that's a great weight for regular/commuter cars, as it'll give you the best MPG, etc... I'm using Mobil one synthetic 0w-40, as I've been doing track days, and that oil is GREAT for track day use as it can handle the higher temps.