Usually when I'm starting a new project, I have something in mind that I'm burning to create - generally either a single overarching Mechanic, or an imagined Place that I want to show off. Or both.
What I always dread is that moment when I have to sit down and write "real" narrative/dialogue (as opposed to placeholder stuff) that people will read. I feel like I'm exposing myself in ways that I don't want to, when I do that kind of earnest writing.
I always look forward to the art and writing. Mapping not so much, but I don't hate it either. My problems are with all the gameplay related stuff. Things like balancing, making the features fun, hunting for bugs...
Look forward to: Writing (world building, character design, story, dialogue, set pieces), Combat design (skill sets, theorycrafting, balancing), Planning (wishlisting, brainstorming)
Dread: Anything related to coding, Cutting things (sometimes really cool ideas have to be let go), Re-writes (no idea why this is so hard for me when I otherwise love writing), Management/Producer stuff (having to tell someone on the project to redo something suuuucks)
Look Forward To: Combat mechanics, dungeon design, puzzles, world-building. I spend a lot of time thinking up new mechanics - cool stuff to make more interesting choices in battle or more fun ways to move around on the map - and I really like designing all the locations in the game to feel different, like giving towns different architecture or making NPCs doing every day tasks to make the game world more interesting to explore.
Dread: Plot. I'm just not great at organizing all my ideas into a coherent plot for some reason. I think up dramatic or comedic scenes and I can use eventing to make them happen, but actually plotting out the course of the plot, and making sure everyone has actual reason to be doing what they are doing, and making sure there is an actual, clear goal to be working towards at all times without slowing things to a glacial pace...well, that's all stuff I'm working on for my current project. I guess I just need better writing skills to make my mechanics and scenes actually work.
Neutral: Database. I don't mind making all the items, switches, variables, abilities, etc. and can do it just fine, but there can be a ton of it so I can't say I actually look forward to doing it.
Looking for to: Writing Characters and Story Parts + Music
Dreading: Debugging/Playtesting (as in, seeing your sh*t over and over and over and over and over and over and over, and yet there's STILL that one little thing that could be better or isn't working that you've gotta dig up everything and fix)
Lookin' forward to: literally everything. The possibilities are boundless, but eventually, I will lean myself to all things visuals
Dread: (if solo) time management and schedules / (if in a team) uncooperative partners
I actually enjoy mapping...what I do not enjoy is the inevitable stress it causes when I freak out over every little tile and whether or not I should Parallax map or not. Sound design and music too. I am not acoustically inclined...
What I do look forward too is writing characters, character dynamics, background characters, non-player characters and background to characters. Did I say I like writing for characters? Because I do!