Generally, Ethernet switches thoritically offer at max (100 mega bit per sec) around 12.5 Megabytes per second. In reality due to other factors this comes down to 10 or 11 Mega bytes per second. If you are looking at streaming a 20 GB - 25 GB Rip Movie then this bandwidth is more than sufficient. However if you go higher than this then there comes a "May or may not" situation to avoid which one should be better off with a gigabit switch having theoritical speeds of 1000 Mega bits per second which is around 125 Megabits per second. In reality even with losses it may come down to 100 / 110 Mega bits per second.
But here is the catch again, you may use cat5 / cat5e cables for connecting other devices at gigabit speeds if the lengths of these wires is less than 3 to 4 metres each to ensure than those wores are eveb supporting gigabit. Beyond than there is another type Cat5e+ (I use this) that will allow you to get gigabit speeds over longer distance. For ultimate interference free transfer you can use cat6 or above but of course at extra price.
I think gigabit switches is the way to go since nowadays even normal usb portable HDDs give 30 Megabytes per sec + transfer speeds and some bigger 3.5 spinning hard disks give 60 - 70 Megabytes + per sec of read speed. Solid state drives give even higher yield. The point being if frequent file transfer over wired network is going to be done then ethernet will become bottleneck.
Btw, I am using the cheap 5 port TP-Link Gigabit switch and it is working fine for me for the last 6 months.
