I would say mine is the Miraculous Journey of Edward Tulane. My teacher read it to the class in third/fourth grade and I fell in love with it. It might be because I loved dolls and stuff like that and related to Abilene. I loved seeing Edward going on all of this adventures and I believed for the longest time that he was like a character in Toy Story. I think my favorite part was when he was with this brother and sister. Although many people don’t like it due to its non-kid friendly topics (abuse, manipulation, death),the book just reminds me a simpler time in my life and when I just started to realize reading was fun.
The Eagleheart series by C.T. Westcott, published in the mid to late '80s. Read them as a teenager and loved them, really funny sci-fi saga. Super hard to find now but I tracked them down a few years ago and re-read them. Laughed my arse off and felt like a kid again, even though the writing isn’t something I’d be interested in nowadays.