I've two #61s;
A four blade Northfield and a two blade congress pen (commonly referred to as a half congress and there was a thread dedicated to that discussion some time ago but I can't find it. I tend to call them half congresses too although IIRC Mr Levine's opinion was that no such pattern existed).
The Tidioute teal bone was my second ever GEC and although I only ever bought one version of that pattern - it remains my most carried and most loved of all my folding knives.
I really like the four blade but don't tend to carry it very much yet as its a relatively recent addition. I love the banner shield and yellow bone though.
There is of course the harder to find and one of a kind #13 ...
... which is based on the same frame as the #61 ...
... but uses a jack formation and is known as a congress jack or Irish jack ...
... and has a considerably longer sheepfoot main.
For me however, I just can't get past this one. I sometimes put it away for a while but it always comes back and has been with me all over the place.
So all I can say is; get one.
- Paul