Yotsuba&!!!!
A slice-of-life manga following the daily adventures of 5-year old Yotsuba Koiwai. It's been serialized in the magazine Dengeki Daioh since 2003 and has a current total of 15 volumes.
The first manga I ever read was Yotsuba, which I stumbled across in the library when I was 8. I had never read anything like it before and I quickly burned through all the volumes available in the library. And now, all these years later, I still adore this series. While it’s true that part of my love is wrapped up in nostalgia, Yotsuba is also just really good. It’s wholesome, sweet, and the comedy is absolutely timeless.
To anyone who hasn't read Yotsuba, I highly recommend it! Even if you aren't a slice-of-life/comedy fan, I think you'll still find something to enjoy.