I wouldn't use a .gif file if I wanted to store a good quality image unless it's really a graphic, like a logo. Jpgs have variable compression, so you can choose the level of compression that allows the image to remain crisp.
Png is great image format, but can't always be read by web sites or web browsers. Copy and paste it and if the software receiving it doesn't recognize it, you could end up with a page of code - it is often code intensive.
IMHO, if you want an image that can be easily copied and pasted into a web site, jpg is the format that is most likely to be recognized by the majority of web software.