Having done some planetary mass/size comparisons, it seemed natural to do the same for stars. The approach of dropping them like marbles didn't seem like a good idea because it would just look weird, and anyway the mass and volumes of the different stars are too different from each other to give much in the way of a meaningful comparison. So instead I imagined what would happen if we replaced our own Sun with other stars. As with the planets, there's both a movie and accompanying image sequence for this. A fairly detailed blog post goes into a bit more about the physics of stars and the choices of how to visualise them.
A Closer Look at VY Canis Majoris
This whole project actually started with a separate sequence of images all on VY Canis Majoris, which was then the largest known star. I never anticipated rendering an animation of this so the still images below took much, much longer to render, but consequently are quite a bit nicer and more visually appealing. I go into more details of how realistic this is (giant stars like this don't really have a clearly-defined surface) on my blog.
I'm actually not very interested in stars so I don't keep up with which star is currently known as the largest. It's entirely possible even larger ones have been found; certainly population III stars would dwarf anything shown here.
Let's repeat the trip through the Solar System, or what's left of it at any rate. From Saturn :
From Uranus :
From Neptune :
From Pluto :
And from Voyager I :