To some people parts and brands are a religious decision. To others it’s a challenge to find the very cheapest options. Personally I like to find quality parts at a good price. When I track down something that works well I want to remember what I got for next time. I’ve created this page of parts and sources so you can benefit from my experience with them. I don’t get a kick back or anything for listing them.
Engine Oil and Filter Service Kit (OEM)
ECS Tuning supplies 6 liters of factory VW 5W40 oil meeting the spec, factory oil filter and o-ring, plus a new magnetic drain plug all for about $71 USD including free shipping. Great deal for the OEM supplies shipped direct to you! You can purchase the kit here.
Engine Oil (aftermarket)

If you are looking for just replacement aftermarket Oil that meets the VW spec, Castrol Edge full synthetic 5W40 is what you need. In the owners manual there is even a recommendation by VW to user Castrol Edge oil, so I suspect the OEM oil is actually just Castrol. You can get a 6 pack of 1 litre bottles from Amazon.com for about $50 USD including free Prime shipping (here). You can also find this find it locally at Walmart in a 5 litre bottle for a mere $22 USD (here). The 5l bottles from the local parts store is the way to go on a budget if you are willing to drive over to get it.
Engine Oil Filter (OEM)

If you are going to buy your oil and filter separately, but want to get the original OEM oil filter, it is VW Part Number 06L 115 562 B. The part includes the filter and new o-ring. You can get one for about $10 from ECS Tuning (here). They also offer them in a 5 pack for about $47 USD (here)

Engine Air Filter
OEM Part Number 5QM 129 620. About $22.17 USD from ShopDAP.com or ECSTuning.com
Cabin Pollen Filter (upgraded aftermarket)

I’ve been partial to upgrading to a better cabin filter for less money. The ATP automotive VA-19 Carbon Activated Premium Cabin Air Filter is an activated charcoal filter to filter out odors as well. Available for about $25 USD from Amazon with free prime shipping (here)
Wiper Blades (OEM)
ECS Tuning offers a set (both blades) VW part number 5G1 998 002 for about $39 USD (here)
Wiper Blades (aftermarket)

I am partial to the Bosch Icon blades. The Drivers side is a 26″ Bosch part number 26OE and is available here for about $28 USD on Amazon with free prime shipping. The passenger side is an 18″ blade Bosch part number 18OE and is available here for about $20 USD on Amazon with free prime shipping.
VAQ Differential Service Kit
Required every 4 years for the GTI with the Performance Pack fancy front torque vectoring differential. Available for about $54 USD from ShopDAP.com here.
Spark Plugs (aftermarket)
Required every 6 years on the direct injection MQB engines according to the official service schedule. An option to the original VW OEM plugs (which as it turns out are made by NGK) I found that the NGK PLFER7A8EG is the correct part. You can source these from Amazon for about $16.50 each, or even find them at the local O’Reilly’s auto parts store for about $14.99 each.
Serpentine Belt

Required every 6 years/60K miles. VW Part Number 06L-903-137-A. I’d suggest you get it from ShopDAP.com and support the people making the helpful videos. Purchase it here for about $30 USD.
Black Wheel Nuts (aftermarket)
The OEM Wheel nuts (bolts actually) are a raw semi shiny metal, with the stupidest black plastic covers/caps over them that are a huge PITA when putting the wheels on and off. Using a pick to pluck the caps out runs the risk of scratching the painted black rims. The better alternative is to replace the wheel nuts/caps with proper black wheel bolts. This set is about $45 (for Qty 20) from USP Motorsports here.