Coroflot is a good place to start. My view of what makes a good portfolio shifts dramatically based on the experience of the hire and a skillset that I would be most looking for in that candidate.
But in general my mental priorities looking at any portfolio: 1 Sketching (Ability to ideate on a brief), 2 Process (How did the idea mature, further showing iteration and convergence), 3 Results (Is the final thing beautiful? Functional? Unique vs derivative? In line with the branding or brief it was trying to solve?) 4 Clean UI (Some people spend more time working on the format of the portfolio than the content, and it’s immediately obvious).