As you can see, Rhino isn't that much taller than Spider-man, but he is certainly bigger.
As for Hulks, they tend to vary slightly depending on the figure. These are all Marvel Universe Hulks.
From left to right: Classic Avengers Three Pack Hulk, Single Carded Hulk, Secret Wars Hulk, and World War Hulk.
Wolverine is pretty small in this line, as he should be, so compared to Hulk, he is clearly smaller. Here we have the Single Carded Hulk compared to the X-Force Three Pack Wolverine.
Here is X-Men First Class Two Pack featuring Wolverine and Sabretooth.
As you can see, Sabretooth is much much larger than Wolverine. Again, Wolverine is very small in this line though, but he probably should be.
Here is a Secret Wars Human Torch next to Fantastic Four Three Pack Thing. Almost the same height, but The Thing is clearly bigger.
Secret Wars Hulk next to Fantastic Four Three Pack Thing.
This is pretty large, as he should be, so most of his figures are Hulk height, but not as thick. I would consider Captain America to be "average" sized. Single carded Thor, Ultimate Giftset Captain America, and Secret Wars Hulk.
There seems to be two version of "larger" characters. The "Hulk" size, which is very thick and tall, and "Colossus" size, which has similar height on Hulk figure, but not as thick. Single carded Juggernaut, First Class Two Pack Wolverine, and X-Men Six Pack Colossus.
X-Force Wolverine and Single carded Apocalypse.
Single carded Thanos and Ultimate Giftset Captain America.
Single carded Juggernaut and X-Men Six Pack Colossus.
Single carded Hulk and Ages of Thunder Thor.
Thor looks short here, but his knees are bent quite a bit. He is about the same height as this Hulk figure.
Generally speaking, Hasbro makes female figures rather small. Secret Wars Human Torch, Fantastic Four Three Pack Invisible Woman and Thing. Reed must have the night off.
Fantastic Four Three Pack Invisible Woman and Secret Wars Hulk.
So, as you can see, most figure that should be large, are. There are obviously exceptions, for example most people think Drax the Destroyer is too small. Overall though, Hulk is definitely bigger than most, and there is pretty good variation in height overall. A 3.75 inch toyline doesn't have just 3.75 inch figures thankfully.
