I saw this in a thread on Scale Rails Online, post a tool you cannot do without when building a model RR. It can be anything you've needed, or may need.
OK. I'll be serious. My #1 favorite, most valuable tool has to be the Dremel. A close second is the vise that goes with it. I've mounted that on an old kitchen cutting board so I can clamp it to my work table.
I'll have to agree with Steve, the hobby knife is the most use tool on my work bench. But, pretty soon I see the soldering pen taking first place once I have to solder all those feeders onto my track soon.
Hmm... Let's see, 85' of double mainline...That's 170', plus 45' of branch line... and then all the passing sidings and spurs... I don't even want to think about the yard ... Soldered every 3'... so that's a whole heep of track times 3 equals... AAAaaaarrrrgh!
The soldering gun may become #1 but I don't think it will be my favorite.