The highest-maintenance guitar I currently own is my Ibanez RG270DX. I bought it new in 2002, modded the thing to hell and back, and somehow it came… back… wrong. Like Louis and Rachel Creed's son, or the ship in Event Horizon. This guitar is haunted. I've had four sets of aftermarket pickups in it, a fret level and dress, the neck taken off and the truss rod tweaked endlessly, the neck glued on, the trem and nut replaced with an OFR, the back of the neck completely refinished with Tru Oil (I can't even remember why I did that), the fretboard dyed ebony, the nut re-attached three times, and multiple sets of stickers applied and removed.
Typical things it does:
-The nut shifts and throws it out of tune. (Yeah, it's an issue caused by my conversion to a top-mount Floyd nut. I'll fix it eventually, but it's just never been a priority since I started playing Jacksons.)
-The high E picks up a phantom buzz at the bridge or the nut. Sometimes removing the pressure pad helps; sometimes it makes it worse.
-I get strange, ghostly noises from the pickups, which I've heard on other guitars with and without EMGs, but never as often or as bad as I get them here. Basically, I pick a high fretted note into a high-gain amp or amp & pedal, let it sustain, and listen. It's like hearing demon voices in the static between radio stations.
The guitar is very comfortable to play, and I love it to death, but I would never, ever gig with it.