I am still in awe at how Wikipedia can have such a site that might not have the trendiest design but can still be accessible to Windows XP users, and that works without JavaScript (even their mobile version, which phones can benefit from less JS (equals more battery life) but for some reason websites have forgotten about it).

For other websites though, it eats your limited data allowance if you are in a unlucky country (even at home if you are in a worse country, thank goodness for unlimited home connections here).