run-of-the-mill, ordinary, middle-of-the-road, average, common, commonplace, everyday, workaday, quotidian, pedestrian, suburban, mundane, mediocre, humdrum, prosaic, lacklustre, unexceptional, indifferent, forgettable, unmemorable, uninspired, unimpressive, unexciting, unspectacular, uneventful, unremarkable, inconsequential, unnoticeable, inconspicuous, characterless, featureless, nondescript, plain, simple, fair, not bad, passable, all right, middling, moderate;

hackneyed, trite, jejune;

North American garden-variety

informal nothing special, no big deal, no great shakes, nothing to write home about, nothing to get excited about, not so hot, not up to much, not much cop, OK, okay, so-so, bog standard, (plain) vanilla, fair-to-middling, a dime a dozen

British informal common or garden

North American informal ornery, bush-league

Australian/New Zealand informal half-pie