Reputable Brands

[Maxstyle]

Tomei US not really the same and Tomei Japan. They may change their name eventually
ARC - No longer in existance
HKS - Great quality but very difficult to get into US as distribution is limited
Blitz - one of the first brands to outsourcing their products but quality control is amazing
Greddy - Owned by a larger group now that owns other brands such as OS Giken. Sold all their tooling during bankruptcy and out source a large majority of their products. Great quality control
MSport - Seriously don't worry. Can't afford it.
Nismo - OEM Quality
DG-5 - Use Korean manufacture. Tuned in Japanese fashion for very aggressive for US style roads
Sard - Great parts. Costly.
Tanabe - Shocks are great when new but they go through lines so quickly that you will not be able to get you shocks serviced in the future.
Do-Luck - Not worth the eccentric styling. Great quality but alternatives are better quality and pricing
Cusco - Amazing product and quality control. Internal manufacturing in Japan. Provide OEM manufacture with Motorsports solutions
Ikeya Formula - Great quality and originators of may of the parts you see copied today. Pricey because of low production numbers. High Quality.
SSR - Amazing wheels. Great product. Part of the TANABE family
Work - Amazing wheels. Great Product. Also part of a larger trading group.
Bride - Amazing Quality but very limited production. Expensive but holds it's value.
Koyo - Quality High but has diminished over the past few years on their new line. Needs some better quality control IMO these days. No real warranty or support.
Apex'i - Amazing Quality and provider of one of the most popular tuning solutions for Japanese cars
Bee-R - More a of Japanese tuning shop. Small electronics. Great for light tuning solutions
Vertex - One of the highest grade body kits. Loyal owner to motorsports culture.
Varis - High Quality kits
Voltex - High Quality Kits
Gargage Mak - High Quality Kits
Advan - Part of the Mackin Industry group in US. Very high quality wheels

"Shity" Brands: I don't entirely agree with this

ISR - Ok brand. Decent for light tuning but life does not last as long. You will buy 2 but over the span of a certain time. Buy one now or 2 isr later
Fortune Auto - Quality components all selected. offering innovative suspension tuning solutions such as digressive piston technology and penske external components.
Mishimoto - Fun fact. US based company that wanted asian sounding automotive name. Mishi was his cat. Add moto and bam. Good warranty but distribution is a bit behind. Make sure item is in stock at your preferred shop
CX Racing - No real foundation. Good if on a budget and just need to get buy. Meh at best
XXR - Surprisingly popular in Japan. Great for 15"s Drifters. Great for getting out there and just driving
Duralast bodykits - Keep your oem.
VIS racing - Keep your oem
Seibon carbon - Slowly improving over time. Best of the replica carbon brand
ESR wheels - No opinion
Varstoen wheels - replica wheels. When you want TE's but don't think you will ever get them.
Cosmis wheels - Affordable semi-unique wheels
JNC wheels - No opinion
Spec clutchs - Hit or miss. Sometimes great sometimes trash. Most the time it's because people are not really matching what they need with what they buy. They over clutch.
Megan Racing - Improved quality over time. Engineer formerly from Tein.
BC racing - Producer of coilovers but no real R&D. Make coils for a number of major brand and takes their design and calls it theirs.
Feal coilovers - Using larger manufacture to produce but valved and spec'd by independent firm in the US. Don't purchase if you're not going to use them to their potential. Will feel like crap if just using for daily street.
Ksport - BC like manufacture
NRG - We all know what it is.
Grip Royal - Mid grade manufacture of wheels. Not Shit but not amazing. It'll due
Rocket bunny - Depends on source. Greddy distributed units have amazing fitment and quality. Alternative Licensed group units are outsourced and do not fit as well
Battle aero - Not truely function. Yes it's a wing but not competition worthy.
ebay stuff - Ebay stuff
Corbeu seats - Great Big Boy Seats.

Here is just some insight on the brands. Everyone has different experiences. Purchase with caution and remember, When you give someone your money, what are they doing with it? Bigger house or more innovation in motorsports. Your call.