After hitting plateaus on a couple of my favorite workouts, I've decided to get back to basics, and do the "5x5 Stronglifts" program, which consists of:

Workout A:
Squats 5x5
Barbell bench press 5x5
Barbell row 5x5

Workout B:
Squats 5x5
Barbell overhead press 5x5
Deadlift 1x5 (although I did 5x5 on this)

You do this three times a week alternating between workout A twice a week with B in the middle, and vice versa, with a day off in between each lift day. The key to this program is increasing the weight of each lift by 5lbs each time you do it. After my first week, I'm excited to see progress. I've still been running 3-4 miles every day, and don't plan on stopping that.