The game I'm playing right now has probably the best starting location for a city I've seen.
River for 10 tiles. Mostly grassland, 4 hills, with some forest, and the following resources:
2 ivory (on grassland and river, great food, production, and commerce)
3 gems (2 on grassland, 1 on hills; all 3 on river. The grassland gems are uber, with a mine they yield 2 food, 1 production, 7 commerce).
1 corn on grassland.
1 horse on grassland.
That city has lots of food, very good production, and superb commerce.
The only thing missing was an ocean tile. A coastal city benefits tremendously on maps where there's other nations early in the game that cities connected by coast. Your religion spreads to them faster, you get more gold from trading with their old cities, and there's later improvements to trade and food for ocean cities.
That same game, my 2nd, 4th, and 5th cities were founded on the coast, each with at least 1 or more resource, and good mix of grassland and hills.