When the series does hit the right note, it becomes an instant classic, practically meme status. When it isn't doing that, it absolutely fails. The characters have very simple personalities, so when the characters get into one of there infamous "funny because it's true" conversations, it can get really exasperating because we know EXACTLY how they're going to react. Konata will relate something in real life to a anime/manga/VN or Tsukasa will fret over something ditzy she does, and Kagami will be OH-SO-EXASPERATED over everything they do. Lather, Rinse, Repeat. However, when the series bothers to try and venture away from its dull formulas, it actually does succeed. When the doujin artist of the group accidentally trips and does a barrel roll (while somehow managing to change the show's art style), all to preserve her drawing hand, it's HILARIOUS. Not because we can relate, but because her passion for her somewhat perverted hobby is both amusing and endearing. When the series makes its forays into the absurd is when it's at its comedic best. This is exactly why even critics of the series will admit that the Anime Tenchou and the Lucky Channel moments are at least a little funny, because there's some effort being put in. In fact, the audience's positive reactions to the absurd humor are probably why the Nichijou anime exists.
On a technical level, the series is smooth and well animated with very little off model shots and the opening scene is way too fun and energetic for a series with such a relaxed pace. If you dislike anime where the characters are bug eyed and colorful, you should probably stay far away from this series. That said, the style is pretty cute if you like your characters to be rounded, short and squishy looking.
Overall, Lucky Star is NOT for everyone. If you're a hardcore Otaku, you'll probably enjoy the series in a Seinfeld sort of way and buy the series (and all it's related merchandise). If you're new to anime or a casual viewer, you'll watch this show and wonder "What's the point?" and find it slow or boring. If you're someone who loves anime but isn't into the otaku lifestyle and prefer more fast-paced humor, you should probably just You Tube
a few of the show's best moments.