So, I picked up Nisekoi mainly because Komi Naoshi is the mangaka, and his previous works (i.e. Double Arts, Personant, Williams, etc.) have been clever and interesting, with a new, inventive spin on old premises. And, to some degree, the same can be said of Nisekoi.
This manga is basically a bunch of harem tropes and such done completely straight and occasionally lampshaded. The only thing that really differs is that the male protagonist is actually, well, likable. And despite all the cliche moments in which he accidentally does something questionable (such as peeping or whatever), he does ultimately come off as well-meaning and not-an-asshole. Whoo!
However, I would not necessarily recommend this manga, especially to those looking for something more serious. It has nice art and decent characters, sure, but at its roots, it's exactly what it appears to be: a silly, romantic, harem comedy.
edit: OK, now 139 chapters in, and it's still the same old, same old. As others have said, there's really no plot (or romance) progression. More girls just keep getting added, which is frustrating (especially because I just want Raku and Onodera to GET TOGETHER ALREADY since they both still like each other, and have since chapter one). But Raku continues to be an overall nice guy, and it's actually pretty amazing that a harem romance comedy can be this inoffensive in its treatment of the female characters. Doesn't really excuse the lack of development, though, but at least that's an upside.