In the past five years I have finally opened up to the idea of giving up on a book or series. My tastes have changed/matured and mostly there are so many books and so little time. I have struggled to get into a book/series that turned out to be amazing, but I have also started books/series with lots of enthusiasm and been underwhelmed at the end. I have had to "force" myself to commit time to a book/series that I totally loved, but I have also breezed through books that I find really weren't that great.
China Meiville - forced myself to finish Perdido Street Station, not really my thing. I tried and gave up on two other books of his and so I donated the four books I had of his and wrote him off my list.
Kameron Hurley - tried book one in the Bel Dame Apocrypha and could not get into it, tried again several months later and it just clicked with me and I loved the trilogy.
Robin Hobb - enjoyed Assassin's Apprentice, started to get annoyed in book two and I skim read the last 50 pages of book three just to finish, Hobb is off my list
Steven Erikson - read FOD and found a lot to like but it was too dense, when I did a re-read before FOL I really loved it
started Belgariad and gave up (thirteen year old me would have loved it), Lord Fouls Bane never drew me in at all and I gave up halfway, the first two Ririya books were good but not great enough for me to invest my time reading more, read R Scott Bakker's first trilogy and liked it but have no interest in reading any more, tried a re-read of Mercedes Lackey and Raymond Feist and gave away their books because they do nothing for me now that I'm not a teen, I set aside runelords because the magic system seemed so stupid
read first Shadows of the Apt book and was underwhelmed so I set it aside but I just recently read another of Tchaikovsky's books and loved it so I plan to give SOTA another whirl
I was loving the Lightbringer series but I stalled out on book four over a year ago and have yet to pick it back up even though I was enjoying it
I can't read everything so I have to narrow the field somehow.
@Gem Windcaster
As far as The Black Company books go here are some hints to help you get interested. I will spoiler them just in case.