There's nothing like real grilled cheese, made in a pan with extra-sharp cheddar cheese and butter. I only make grilled cheese a few times a year, and for me it is a special occasion truly worth its weight in LactAid pills.
The best gluten-free grilled cheese I've had was made with Ener-G Tapioca Loaf, which runs a bit dry but works well for sandwiches and is amazing when pan-grilled in butter. I hear it's also great for making gluten-free stuffing for Thanksgiving. The second runner up is I Can Eat That bread which is available only in the greater San Francisco Bay Area. It is purchased frozen and has to be baked at home. The sandwich in this photo is made on Food for Life Brown Rice Bread, which has to be well-toasted before using it for grilled cheese, since like most of Food for Life's loaves it has a good flavor but a tendency towards gumminess. I look forward to venturing into the world of breadmaking this winter. I haven't tried baking my own bread yet, and I have a feeling it won't be hard to outdo storebought gluten-free breads!
For a more sophisticated grilled cheese sandwich, I sometimes add a slice of tomato and kalamata olive tapenade.