I think the best example was the fireplace... when we moved in there was a hearth that went all across one wall of the living room. Squared off, and stuck out appx 18"... it had been covered in rectangular tiles that were falling off and critters had been known to crawl into the house through the hole. Landlord didn't even bother slapping the tiles back on, much less fixing the thing... but he gave us permission to do so. We go to rip out the old to put in totally new and find that when he put in the hearth he just slapped it on OVER the carpet... and from our neighbors learned that for years there'd been a hole outside where cats (and who knows what else) got in. Once the landlord came and boarded it up... WITH KITTENS CRYING IN IT... anywho, when we pulled it up we found the old carpet, old padding which crunched when rolled up... along with a good 5" of leaves and debris and a full possum skeleton as well.
I think that MIGHT be the best example of laziness... though the cat urine & spray laden carpet, curtains and walls (the microwave was right next to it so he left us thinking those stains were gravy from the previous tenant -his mom-'s shaking hands... it wasn't) certainly rank high on the list.... the carpet in DD's room where a possum had gotten in and locked in and died and was left to rot wasn't great either... but I still think the hearth wins the pool.
Most annoying goes to the thermostat... "someone" had disabled it by removing the wire that runs from switch to circuit... but he didn't bother telling us that it had been disabled so we just froze the first time it was cold... finally got ahold of my A/C uncle (since landlord wouldn't answer the dang phone) and he walked me through trouble shooting... I fixed it, not hard, but was supremely pizzed that we froze because land was such a goober... I mean REALLY, why disable the heater when you shut the electric off in the house?!!? GAH! Sec ond in that category is the wall oven... which doesn't work and never has... when DH mentioned this to him he said "That's too bad" and walked away... that oven is TINY... maybe, MAYBE a couple inches bigger than the toaster oven I use... so not really worth the effort of trying to replace it... but still annoying that Land won't even try.
And since we can't afford a rent hike we lay low and deal... frustrating.