What sort of preview should I use when importing photos into Lightroom?

I was recently wondering how to decide what kind of preview to choose when importing photos into Adobe Photoshop Lightroom 2.5. Basically, you have four options:

• Minimal Preview
• Embedded and Sidecar Preview
• Standard Preview
• 1:1 Preview

These are very different, since they use different time to render and also take up different amount of space on your HDD in the database. So which one to choose? 

I personally opt for Standard preview most of the time - it gives you previews big enough to go through your pictures quickly in their Loupe resolution (almost fullscreen). That is great for most of the occasion, and you can of course still always zoom in (takese maybe two seconds then).

These two seconds you would save if you chose 1:1 Preview option, since that is the one where the whole image in full resolution is rendered. Ideal when you need to zoom in often, perhaps to check the noise level or sharpness, or when looking for little details. Obviously, this takes up a lot of space on HDD.

If space is the key factor, go for either one of the first two, the difference is negligable - Minimal renders just the very small preview, Embedded and Sidecar adds the internal preview (not always accurate, mind you).

• More details in this article on Preview options in Lightroom