Low premiums and they offer an HSA plan.
The best things are work from home (varies by dept), paid volunteer day, paid maternity leave. The worst things are subpar 401K match, lack of paternity leave. The insurance is OK.
Best things are 401K with good company match and work from home opportunities depending on what department your in. They're going to offer a paid volunteering day in 2016 I've heard. Insurance is ok, maybe pretty good I'm not sure. Worst things are vacation is capped at three weeks even if you work there forever and sales people don't get paid vacation, and they give time off for only 5 or 6 holidays per year (like there's no timeoff for Christmas Eve or New Years Eve, or the day after Thanksgiving).
Great overall benefits; pretty much everything standard you could ask for. As of now they only offer high deductible health plans, but it's still great coverage and very reasonably priced. Lots of small miscellaneous perks here and there— entries into cash drawings, free food about once a week, etc. Pretty sizable performance bonuses the several years I've been here, and I don't see that going away any time soon.
Health insurance is very expensive and they only offer HSA plans.
List based on reports from current and former employees. It may not be complete.