Gaming doesn't use very much data so set that computer in a class higher than the class that has netflix on it.
Then set the gaming class at 100% for both upload and download.
Then set the netflix class at 80% of your download speed. If you are lazy, you can also set uploads at 80%, but at that rate, if more than one person is streaming, then upload requests will saturate download links and your download gaming packets will get lost with the netflix traffic. That will increase latency, but will be nicer to the people on your network to stream the most bandwidth at any given time with some increase to your latency.
I recommend 150kbps upload per 6mbps of traffic. So if you have a 9mbps download speed, then I recommend max 225kbps upload for netflix requests. This will provide more than enough overhead for your gaming traffic uploads, but download traffic for both gaming and netflix may get congested at the router or the ISP. If you find your latency is still high, then lower the upload limit for netflix traffic.
You can't really control the traffic you get on downstream, it's mostly via upstream.
Here are the modified classes and priorities you need to know.
TCP
Dst Port: 80,443,8080
Transferred: 0 - 512KB High Web Surfing 8 Max Speed 10000/425
TCP
Dst Port: 80,443,8080
Transferred: 8192KB+ Med Netflix 10 Max Speed 6000/150
TCP
Dst Port: 80,443,8080
Transferred: 512 - 8192KB Low Web Surfing 11 Max Speed 10000/400
This will catch Netflix traffic and put it in a class just below normal websurfing so that all Websurfing will feel mostly zippy while still allowing Netflix to have sufficent bandwidth to stream, but not overcome your connection.
Now create a new rule with your computer's IP address.
SRC IP: 192.168.1.51
Port:111,222,333,444 Highest Gaming 7 Max Speed 10000/425
Now your computer gaming ports and data will processed the quickest and sent in and out the fastest. Since gaming packets are small, no one will notice the difference, but you will notice the reduced latency.
Use this on a good quality router.