Thuja

Roll20's excellent - it's got a lot of quality-of-life improvements that take advantage of the virtual nature of the tabletop (as opposed to, say, Tabletop Simulator.) '/roll 6d6>5' will immediately tell you how many 5+ successes you get on 6d6, summed at the bottom; there's a built in ruler and you can change the geometry depending on the system; at the more complex end you can create macros to do all sorts of things (want to just press different buttons to fire a weapon on semi- or full-auto, or to choose what negative modifier to put on a power strike? That can be done.) Best of all, you don't even need to use these - if you have a paper character sheet (although most systems have virtual ones you can use) then you can just type in the rolls manually ('/roll ndx') and use it as a combined table and dice roller.

As to webcam, no - I never use one (I don't even have one for that matter.) The games I've played have tended to use Skype or Discord though, as Roll20's built-in systems are (or at least used to be) rather iffy when it came to speech.