Dice Tower reviews recommend Jamaica as a must have racing game but Lewis and Clark is rated higher. Your opinions? Which do you like better and why?
Those are very different games.
Jamaica is light and quick and mostly a racing game (with some non-racing elements added).
Lewis & Clark is not really mainly a racing game in the stricter sense. Is a mix of deckbuilding, worker Placement, card managemnet and trading goods, where the victory point scale is disguised as a river, at the end of which you have to arrive first... Also it is rather heavy and brainy, and takes about 2-3 hours (with 4 or 5).
L&C is a very interesting and exceptional game, but the question here would not be, which game is better, but what kind of game are you looking for?
By the way, the best racing games in the stricter sense are Mush! Mush!: Snow Tails 2, Formula D and TurfMaster.