The show does occasionally come up to my limit, and briefly tipped over, but it is saved by the fact that Veronica is insane, and watching Logan run into the buzzsaw that is Veronica's crazy is quality entertainment, as he is repeatedly baffled, dumped, and finally arrested.
I think I have a more pathological interpretation of VM than most, but the show didn't work for me until I took "Veronica is crazy" as a central organizing principle. I didn't believe that the shallow and naive Veronica of the flashbacks was the same person as the year later uberdetective Veronica; so Veronica's crazy, and this is an example of pathological obsession. Similarly, the fact that apart from her parents, she can only deal in human relationships in the context of favors done or owed might have been irritating, except: Veronica is crazy! This also made her hooking up with Logan believable, as he had just done her a major favor and thus was on her gameboard.
My darker take on the show carries over elsewhere; while I loved Keith Mars's relationship with Veronica, I thought he was a crap sheriff and deserved to lose his job. This is probably because I have seen far more people fucked over by police getting locked into a wrong theory on 'instinct' than I have seen rich people get away with murder because they are rich. And given that all the significant evidence was discovered later by his daughter, his focusing on the Kanes was all about his issues and nothing to do with evidence.
They seemed to realize this very late in the run and shoved in a scene to give Keith some actual evidence, but said scene required that you believe that a high powered technology executive who had already proved himself quite familiar with lawyers (and would later prove himself steely-minded enough to call his personal security to initiate a coverup while he's actually sitting beside the newly discovered dead body of his daughter) and who knew that he was lying (to cover up an affair) would allow himself and his wife to be interviewed for hours on details instead of calling his lawyer.
In fact, the forcing of characters into OOC actions for plot thrills is what keeps the show from greatness for me. Not all of them are as bad as when Veronica's temporary boyfriend turns into a cackling supervillain in the last five minutes of his time on the show, but it kept happening and pulling me out. And it made the season finale a real letdown. I completely approved of her father saving Veronica; it honored their relationship nicely, and was a tip to the reality that teenage girls can't be superheros all the time. And her disintegrating into hysteria at the very last was fine, because she couldn't do anything and was in the middle of the fire. And I can even see why, for both legal reasons and her general distaste of the physical over the mental/social, she might not opt to beat Aaron's head in with a tire iron while he was conveniently unconscious. But the sudden descent into horror movie bimbo behavior annoyed the fuck out of me. Instead of heading off into the woods where he'd never find her and walking over to another house, or simply picking up one of the many objects on the deck and smashing the sliding door in to get to a phone, she shrieks and runs around.
However, there are some things it does very well, particularly in comparison to Buffy. It sets up parallels without needing to beat your head in with them the way Buffy did; for example, we just watched the second season corrupt real estate mogul story. It was content to set up the teacher who is too moral to dump his losses on another and the mogul who takes the money and dumps his family without a thought, and lets you work out the parallels and moral yourself. Buffy would have felt the need to have a conversation between two characters about how isn't it sad how Teacher X lost his money, good people can't get rich because they can't leave their morals behind, like Real Estate Mogul guy. Orr a cut from the teacher's picture of the sailboat to Rich Real Estate mogul sailing in the Caribbean.
It also has some very pretty symbolism. The triune setup of the bus crash, with the poor kids in the bus, the 09'ers in their limo, and Veronica standing aside from them both on the motorcycle was very nice.
*Sometimes I think fans can be their show's worst enemy. Apart from Loganphilia, the fact that I've seen exactly one Supernatural post that talks about even plot, and zero meta ones amid a thousand "Sam and Dean are so HOT!" has led me to conclude the show itself is crap.