Personally, I thought it was a pretty terrific finale. Much more emotionally affecting than I would have anticipated. I give big credit to the cast for keeping the characters likable during many older episodes that simply were not well written at all. But this episode hit every beat I could've asked for.
One last Jeffster performance that folded into the plot perfectly. Wrapping their story by sending them off to Germany to become the next Hasselhoff-ian musical sensation was genius.
Chuck taking out Casey's chopper with Casey's own gun killed me. Silly, but damned funny.
The Buy More merging with Subway managed to include one more bit of product placement in a way that actually enhanced the show.
The hopeful without being saccharine final scene made me smile, and I generally hate romances.
The best compliment I can give the finale is that for a show I hadn't truly cared about for a while, I was completely onboard throughout.