Diigo, Stubmleupon, Xmarks. Many alternatives. Are they any good when it comes to tagging and browser integration?
Would love to be proven wrong, but even the "people's champion" here, pinboard, doesn't even approach the usability or functionality of delicious.
There's no first party Chrome extension. The best third party one, felicious, doesn't do tag completion much less suggested tags. The latency between adding a bookmark and having felicious show it is atrocious, even with 'auto-sync' enabled.
Ugh.