For me, old-school D&D and its clones have nailed the monster presentation format.
DCC RPG is my favorite in this regard.
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That's everything you need to run that ghoul. Except the paralysis save. All you need is "DC 14 Will save or be paralyzed, unable to move or take any physical action for 1d6 hours" from the description and you're set. The full description is one paragraph of stats (above) and four paragraphs of text.
As much as I love D&D 4E's monster design, I don't need or want a stat block that takes up half a page.
I love the D&D 2E monster ecology and more in-depth descriptions, but I don't like the stat block format used. It eats up way too much room. Gimme the above condensed stat block and the better descriptions.
For me, art is extra. If you need art, make it black & white line art like old-school D&D and its clones. Again, DCC RPG is my favorite of them for this.
Old-School Essentials gets an honorable mention as it's very close to the top of my list.