Tested a few of the affected sites you're mentioning and things seem to look OK for me so far.
Can you post a few tests here please?
Specifically looking for a ping, traceroute or MTR.
The more info we have, the better we can diagnose.
I have a similar problem to Hummercellc. Facebook is a useful site to test with, so here are some results. The ping test is fine though:
$ ping -c 3 www.facebook.com
PING star-mini.c10r.facebook.com (31.13.91.36) 56(84) bytes of data.
64 bytes from edge-star-mini-shv-01-ams3.facebook.com (31.13.91.36): icmp_seq=1 ttl=79 time=179 ms
64 bytes from edge-star-mini-shv-01-ams3.facebook.com (31.13.91.36): icmp_seq=2 ttl=79 time=180 ms
64 bytes from edge-star-mini-shv-01-ams3.facebook.com (31.13.91.36): icmp_seq=3 ttl=79 time=182 ms
--- star-mini.c10r.facebook.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2000ms
rtt min/avg/max/mdev = 179.879/181.060/182.894/1.359 ms
the traceroute shows that traffic follows multiple routes:
$ traceroute www.facebook.com
traceroute to www.facebook.com (31.13.91.36), 30 hops max, 60 byte packets
1 adsl.wfeet.za.net (192.168.1.1) 1.634 ms 1.766 ms 1.981 ms
2 * * *
3 cpt-up2.ip.adsl.co.za (169.1.5.106) 39.015 ms 40.883 ms 42.788 ms
4 cpt-net1.ip.adsl.co.za (169.1.5.128) 45.977 ms 47.615 ms 50.262 ms
5 41.164.52.40 (41.164.52.40) 53.402 ms 55.231 ms 58.983 ms
6 if-ae-7-0.tcore1.KLT-Cape-Town.as6453.net (41.206.164.53) 72.173 ms 70.802 ms if-ae-7-0.tcore2.KLT-Cape-Town.as6453.net (41.206.165.25) 87.575 ms
7 if-ae-2-2.tcore1.KLT-Cape-Town.as6453.net (41.206.164.253) 213.574 ms if-ae-5-80.tcore2.PV9-Lisbon.as6453.net (80.231.159.57) 180.898 ms if-p-6.core2.PV9-Lisbon.as6453.net (41.206.164.6) 155.901 ms
8 if-xe-0-0-0-2000.tcore1.PV9-Lisbon.as6453.net (80.231.158.1) 189.136 ms if-ae-2-2.tcore1.PV9-Lisbon.as6453.net (80.231.158.5) 190.084 ms if-p-6.core2.PV9-Lisbon.as6453.net (41.206.164.6) 156.073 ms
9 if-ae-2-2.tcore1.PV9-Lisbon.as6453.net (80.231.158.5) 197.721 ms 188.385 ms 199.825 ms
10 if-ae-1-3.tcore1.SV8-Highbridge.as6453.net (80.231.158.30) 174.556 ms if-ae-2-2.tcore2.SV8-Highbridge.as6453.net (80.231.139.1) 206.370 ms if-ae-1-3.tcore1.SV8-Highbridge.as6453.net (80.231.158.30) 174.115 ms
11 if-ae-2-2.tcore2.SV8-Highbridge.as6453.net (80.231.139.1) 186.686 ms 173.538 ms if-ae-11-2.tcore1.L78-London.as6453.net (80.231.139.42) 179.495 ms
12 if-ae-2-2.tcore1.L78-London.as6453.net (80.231.131.2) 183.871 ms if-ae-17-2.tcore1.LDN-London.as6453.net (80.231.130.130) 172.587 ms if-ae-11-2.tcore1.L78-London.as6453.net (80.231.139.42) 185.533 ms
13 195.219.83.186 (195.219.83.186) 175.436 ms 175.236 ms 173.966 ms
14 ae-4.r23.londen03.uk.bb.gin.ntt.net (129.250.5.40) 172.650 ms 180.001 ms 173.017 ms
15 ae-2.r24.amstnl02.nl.bb.gin.ntt.net (129.250.5.2) 177.968 ms 179.732 ms 182.303 ms
16 ae-2.r24.amstnl02.nl.bb.gin.ntt.net (129.250.5.2) 183.550 ms ae-2.r03.amstnl02.nl.bb.gin.ntt.net (129.250.2.211) 174.110 ms ae-1.r02.amstnl02.nl.bb.gin.ntt.net (129.250.2.113) 177.404 ms
17 ae-2.r03.amstnl02.nl.bb.gin.ntt.net (129.250.2.211) 180.369 ms ae-1.r02.amstnl02.nl.bb.gin.ntt.net (129.250.2.113) 173.501 ms ae-2.r03.amstnl02.nl.bb.gin.ntt.net (129.250.2.211) 173.514 ms
18 81.20.67.198 (81.20.67.198) 172.995 ms ae-0.facebook.amstnl02.nl.bb.gin.ntt.net (81.20.64.22) 177.438 ms ae1.bb02.ams2.tfbnw.net (31.13.29.90) 182.699 ms
19 be8.bb01.ams3.tfbnw.net (31.13.27.67) 175.307 ms ae1.bb01.ams2.tfbnw.net (31.13.29.86) 173.415 ms psw01b.ams3.tfbnw.net (173.252.66.204) 184.482 ms
20 edge-star-mini-shv-01-ams3.facebook.com (31.13.91.36) 216.035 ms 337.487 ms 339.891 ms
I had a look at the page load times using Chrome's Developer Tools and they are, during the problem time (which seems to be between 6 and 8 pm especially) extreme. The url https://www.facebook.com took 1.2 minutes to load in one test. The page appears piece by piece - first the basic frame and then components like the chat interface and so on. The problem doesn't seem to be related to simple latency or packet loss, there is more than that going on here.