(For those curious, the initial question asked about underrated characters)

Overall, in terms of chars without dumptrucks, absolutely Daniella from Haunting Ground by a landslide. With a dumptruck would probably mostly refer to people's OCs for now since I can't think of any very large established characters atm, so I'll say Fiffer's robot girl D33-D (not to toot my own horn but I also really like Mippi, but I assumed you wanted me to mention someone else's character).