fishslayer got it on the head. Most calmed water would be Jenks, followed by Gregory, due to the canopy of trees surround the entire water. Silverwood, Big Bear, Perris, and Elsinore are wide open, and a nice breeze will make you work like you wouldn't believe.
At this point in time, Gregory is best, since tubing just opened up. $7 launch fee from the marina/boat launch. Make sure to call first to ensure someone is there to verify your launch. The launch starts around 8am I believe. I normally launch around 9am. By 1PM, you should be able to catch yourself quite a bit of panfish, trouts, and occasional huge catfish.
Jenks is $10 for parking. Launch at the flat dirt spots, and go nuts. Suggestion would be comfy waders. Bacteria level is low after all the snow melt, but if your immune system is weak due to a previous cold, allergies like me, or just a small infection, you'll be a nice immuno-suppressive attack from the bacteria remaining in the water. Jenks is great for all the isolate fish that have a chance to really grow in the past months.