It depends on what you want to spend...IMO they are all must haves.
There are several other threads on this same topic, do a search and you will find plenty of details, including this one:
http://www.xoutpost.com/x5-e70-forum/...reference.html
A few comments:
1. Tech Package- IMO a must, despite the Navs shortcomings.
2. Premium Sound- Its awesome- but you must listen to CD's or HD radio to appreciate it, again well worth $ imo.
3. Cold Weather Package is nice even in warmer climates like South Louisiana where it has come in handy for me....except of course the Ski bag.
4. Sport Package- LOVE IT!!