Orange-Bacon Brussels sprouts: Slice 1 orange with the rind on and layer it on the baking sheet first. Dice up 1/2 lb of bacon and mix it in with the sprouts. The sprouts should be sitting on top of the oranges while cooking - embedding them with orange flavor.
Maple Brussels sprouts: Roast the sprouts as per the basic recipe. Before serving, toss with 1/4 cup maple syrup and 1 tbls balsamic vinegar. (Maple syrup can be really sweet - the balsamic vinegar adds a bit of contrast without being too strong.)
Sesame Brussels sprouts: Roast the Brussels sprouts according to the basic recipe. Before serving, toss with 1/2 cup bottled Hoisin sauce, 1/4 cup toasted sesame seeds and a dash or two of sesame oil.