Title, give your reasons.
For me:
Hero: Silencer. As a mostly pos2/pos4 player, I hate needing to buy multiple sources of dispel to actually play my hero.
Ability: Nether Ward. Pugna is a very active hero, and Nether Ward is a fully passive ability. Since we're gradually removing hard counters from the game, I also dislike how it instakills high MP int heroes like CM/Lion/Rhasta/Sky.
Ultimate: Call Down. It simply looks like a regular skill instead of a proper ultimate. Most heroes have iconic ultimates, but Gyro simply doesn't.
Item: Meteor Hammer. I hate how the interaction with OD forced multiple nerfs of both the item and the hero.
Talent: +1.2% Feast Lifesteal. This is grossly weak as a level25 talent ; I'd be okay if it also increased Naix damage.
Source: https://www.reddit.com/r/DotA2/comments/yzg65u/which_heroabilityultimateitemtalent_you_want/