If you are going to take the time to rip your cd's into mp3, rip them at the highest rate.
If you are going to take the time to rip them into another format, rip them at the highest format you can.
If you are going to rip them in a lossless format, you need to decide which format you want and which one will be the most compatible with what you are doing and what you want to do.
That is what I have been doing anyway... I have started to move away from Mp3 and stared ripping everything at apple lossless. If want the lossless ripped into a smaller file, I don't have to look for the cd and re-rip, I just grab the files in question and start converting. This does take up a little more space but hd space is cheap these days.