The Shield was great. I think it's not remembered by some because it was an early F/X show. I skipped the original run because I thought "It's network tv, how good could it be?". I only got into it when a local tv channel started running edited for broadcast versions really late at night, and thought it was pretty good in that form, so let's watch the real version.
Also adding Boardwalk Empire to the list of worthy HBO shows too.