Taleo makes a great job making it as painful as possible to search and apply for jobs. I find it pretty funny a "hack" of how to look through taleo listings is in an article about unadvertised jobs.
Yup. On the one hand, recruiting is hardly the rocket science of software engineering, and on the other hand, it's hard to imagine a more user-unfriendly system than Taleo, yet somehow they seem to dominate the market.
Silk Road and SuccessFactors are just as terrible in my opinion but seem to also have a healthy percentage of the market. I believe all these HR software systems follow a similar pattern of starting out solving a fairly simple problem, then as Sales brings in more and more disparate customers, the developers keep tacking on stuff until it is a hodgepodge mess.