A while ago there was a poll on what board games were our favorites or least favorites. I felt a little bad because the information I gave wasn't very clear or complete. I think it's because I'd put my bean in the bucket and didn't really give it too much thought. Looking back on it, I figure someone asked the question because they wanted some insight for some important project--and darn it I'm opinionated and verbose!
What I hate in a boardgame
I hate an ugly board that wastes a lot of space--the kind that only have like 10 squares on the whole thing and are in clashing primary colors. I hate ugly generic peices that look like pawns or whatever and gameplay that's vague and purposeless--roll a die and move that many spaces. I hate games that feel like you got cheated because it's just the ugly board, a bag of little pawns, and an ugly die.
What I love in a boardgame
I love a pretty board that actually represents something. I love Clue and Risk for that reason. The boards are lavish and mean something. Even more I love when a normal game I'm used to is tied into a product line I love. For example normal Clue was okay...D&D Clue is AWESOME! Star Wars Life was great! Lord of the Rings Risk was the coolest thing ever! You take the basic game and kick it up a level by tying it in cleverly with something else I like a lot. Much better even if it comes with lots of little minis that I could use for something completely different. I've been much tempted in the past to buy the Doom boardgame just for the minis. I'd buy Lord of the Rings Risk just for the map and the minis. That's a good thing. Good dice are another bonus to any game. I love good dice, and might buy an otherwise bleh boardgame if it promised truly unique dice in decent numbers (at least 4). I love games that incorporate cards as a randomizing element, particularly if said cards are pretty. I love little counters and things, like you get as mana in Magic. Any little toys and cards and bits make a game tremendously more fun and valuable. Also any game that has different ways to play it--optional rules, sidequests, or at least enough complexity that it lends itself to creating those sorts of things will get played over and over.
One of my favorite games was the Jurassic Park game. It was great! You had a map that was pretty much the island from the movie divided into a grid. Each character starts somewhere on the map and has to get to the main foyer building. Every time a character moves, they roll a big ten sided die. There are various dinosaurs--mostly velociraptors and one big awesome T-rex. At the end of your turn you get to move whatever dinosaurs come up on the die. The raptors move more often, but not as far. The T-rex moves less often, but when it does it can clear the entire park. If a dinosaur lands base to base with another figure, that figure has to "hide" until someone moves the dinosaur away. It's basically a race to get to the compound first. It's a really simple premise, but really fun in gameplay and its a nice looking game. It's also full of fun concepts that could translate into a cool fantasy monsters vs. adventurers or armies versus armies kind of game.