There are all kinds of doodads available for Firefox, which is what I use. But I could never find a "back button" that would back up 2 pages with one click. They either backed up one page with a left click, or you had to right click to get a menu to choose where you wanted to go back to. In that case if you only wanted to go back 2 pages you still had to click twice. Either left click twice, or right click and select. 2 clicks.
To soothe my nerves I made a Bookmarklet called Double Back and put it on my personal bookmarks toolbar. You left click it. If there isn't enough history to go back 2 pages it only tries to go back 1, to avoid clicking it for nothing. Otherwise it goes back 2.
Just make a bookmark on your bookmarks toolbar. I named it Double Back but it's up to you what you want to call it. Past this line into the Location: