For Windows, I would recommend dbPoweramp, foobar2000 or EAC. Both support AccurateRip, which makes sure your rip is good (provided it already exists in the database). A new and interesting project is CUETools which also supports error correction if the disc is in their database (unfortunately not so likely with most tango cds at this time).
Both CUETools and foobar2000 support checking previously ripped tracks against the AccurateRip database. (If ripped to a lossless format, that is.)
For Mac, XLD looks very promising, but I am not a Mac user, so I haven’t tried it myself.
Unless you are really pressed on space, make sure you rip to a lossless format such as flac or equivalent (e.g. alac, supported by iTunes). This way you won’t have to worry about sound quality or ever ripping your music again, as transcoding between lossy formats is not recommended. And do make a backup.
If you go for lossy compression (which should be good enough for most purposes), mp3 is most widely supported, aac/wma or vorbis are more modern codecs and in general provide better quality at the same bitrate, at least for lower bitrates.