Is Monster really worth watching? I intended to sometime ago until I saw the number of episodes. I have trouble getting through anything that long.

Well, it depends on your tastes. If you watch anime for wacky Lucky Stars or monstrously explosive stuff like TTGL, then Monster wouldn't be your cuppa tea, being more of a drama. But otherwise? Naoki really did his research on this, and the narrative is nothing short of amazing.

So, yeah, it is.

Also, I'd recommend 20th Century Boys, if you haven't read that yet.