Modems/Routers will inevitably pull a little bit of power but most are in the sub 15W range, so not negligible by any means, but probably about 10p per day per device, you also can't put them in standby easily or turn them off without losing the service they provide. The issue is more about high draw items which are on continuously, I was in the bad habit of leaving my computer on most of the time, which pulls about 90W at idle, so was costing me around £1 per day, I now have it set to go into standby after I've been away for 15mins, dropping power consumption down to around 5W (three monitors, high power PC, plus a lot of peripherals).
Unless the TVs are older (say older than 10 years or so) then standby should make power draw so low that it's not an issue (see Regulatory Standby, which the EU introduced in 2008 meaning that consumer electronics in standby mode must draw very small amounts of power).
Smart plugs are great, but I'm not convinced of their ability to give energy savings, TP link plugs are decent in that they allow you to actually monitor consumption, so a couple of those might be useful.