I totally agree with you that "There Will Be Blood" was a big disappointment. Excellent acting and cinematography can't cover up for the film's many flaws. The plot went absolutely nowhere for the first two hours, which were just a long, meandering buildup for the action in the final 20 minutes, which was entertaining, but nothing special. 158 minutes of my life I'll never get back.
Juno, on the other hand, was outstanding. The only thing I didn't like about it was the soundtrack, which actually got in the way of enjoying the film in several places. But the acting, plot, dialogue, etc. were all very well done.