We loved the fireworks view from the Cali Grill. Both California Grill and Narcoosee's are 2 TS credits, though.
Whether the meals are big enough to share REALLY depends on your eating habits. For my husband and I, the only meals we could NOT comfortably share were the CS lunches in the parks. When on the dining plan, because you get appetizer and dessert as well as your entree, we could have EASILY shared any of our table service meals. But, I confess, I am a VERY light eater. We did NOT share TS meals since it was just the two of us and our first trip to the world, but are certainly planning to next year. (Examples: we ate dinners at Cali Grill, Teppanyaki, 50's Prime Time, Kona Cafe and Le Cellier, we also had breakfast at CRT. The only place we couldn't have shared was at CRT, and I don't know if they allow you to share there anyway.) Many, many others have said that meals at all of these places are NOT big enough to share. What tips it for us is the appetizer and dessert.
What to do with the extra credits? We will eat at signature restaurants or have an extra meal.
Best 1 TS meals? Le Cellier (I think, hands down). We will NOT do Teppanyaki again, as I thought it was pretty standard habachi fare - but that's just us (many disagree with me!) On the other hand, I LOVED 50's PT, and it is hardly high cuisine - perhaps those last two say something about my taste? I will point out that Coral Reef has gone to 1 TS, but I have never eaten there, so cannot give an opinion as to how good it is.
Check out the many dining reviews that appear on the boards - they are usually very informative (and entertaining!)
Have fun planning!