The top-rated indoor grills compare quite favorably when paired up against outdoor grills. While individuals don't get the same flavor as a charcoal grill, many indoor grills are able to cook similarly to outdoor grills without all the cleanup.
For example, many of the top indoor grills are either open air or capable of being folded open, which mimics the outdoor style of cooking. Units such as the Zojirushi EB-CC15 indoor electric grill and the DeLonghi Alfredo healthy grill BG24 are praised for their ability to mimic outdoor grills, but are also very efficient and very quick to reach temperature.
Another indoor grill, the Livart orange BBQ grill, is designed for yakitori grilling, but can be used for traditional grilling as well. Not only does it resemble a more traditional grill, but About.com states that it provided one of the closest tastes to outdoor grilling possible with indoor grills. Unfortunately, the grill is fairly small, only able to handle enough food for two people.
Other indoor grills, such as the Cuisinart griddler GR-4, are specifically designed to copy the outdoor grill experience as closely as possible. With the ability to flip open to grill and possessing an oversized lid, this indoor grill was designed to handle very large burgers and sandwiches that could previously only be cooked on outdoor grills.