UML diagrams that are actually pretty?

I'm looking for a diagramming software that would produce good looking output. It doesn't need to support everything (or even much) from UML, is doesn't need to have code engineering functions or anything, it just needs to produce visually interesting output.

Here is a couple of samples of products that I consider ugly / not good enough: Visio with default UML stencils (didn't find better looking ones), Enterprise Architect, Dia, ArgoUML and many other "professional" UML tools.

A couple of visually compelling tools that I considered (but found issues with):

Visual Studio class diagrams - just for .NET classes but the output is miles better than what UML tools typically produce
NClass - similar to VS's class diagrams but I could not find the "pretty", blue skin anywhere
yuml.me - very nice but lacking some advanced layout options. I have to say that I find their style almost ideal for high-level diagrams - they look sketchy which is good.
Balsamiq - I think Joel used this for hginit.com and I liked it. However, it's not suited for creating software diagrams so I can imagine it would be quite a lot of work
MS Word has actually quite a good graphics engine but I'd rather leave this as a choice of the last resort

I'd be grateful for any good tips.

Solution

Visio seems to be the closest match for what I'm looking, something between vector editor and a software diagramming tool with decent formatting and layout options. Not optimal on many levels but the most flexible tool I tried so far.