Side note: Liver = awesome.

(edit- just sharing that opinion)
I love the taste of liver, but I'm not so fond of all those tubes. It's also tricky to cook well, just a moment's inattention can leave it like leather, although I suppose casseroling rather than grilling it gives a bit more leeway.
Ah, I've almost always had it chopped. Never tried to grill it myself. If I did, I doubt it would come out well.

Indeed. My favourite part of a rabbit.
At my house we typically wrap them in aluminum foil and 'grill' them on the stove for a few minutes, then make chopped liver out of them. You do have to be careful while cooking them, though, as it's really easy to burn them if you let it go too long.
In my opinion, the best way to prepare liver is to start with a cast iron fry pan, half a stick of butter, and a large onion, sliced. Cook the onion in the butter over medium heat until soft and golden. Lightly dredge the liver in seasoned flour and add to the pan. Cook on both sides until nicely browned and just a couple minutes past the point where the blood stops bubbling out the top side.
Of course, this is just my opinion and others may disagree.