Jeri Ryan was a fortunate choice to play Seven of Nine, and not only for her physical attributes, although that never hurts. She is one smart cookie, and she played the Borg perfectly, with just the right mixture of cold scorn and nervous vulnerability. She made all the actors better when they had a scene with her, but she really shone when matched against Mulgrew. Their scenes literally jump off the screen for me. I hate what they did with her character in "Endgame," however. Such a shame to see a unique and compelling character reduced to an ingenue just to boost the ratings.
That she has worked steadily since Voyager ended is a testament to her acting abilities. If she had been nothing but eye candy on Voyager, she would have faded quickly into the scenery. It is truly a shame that her costume is remembered better than her acting by many fans. For that reason alone, I think she should have been dressed in something closer to a Starfleet uniform after the first two or three episodes.