Which ccie track is best?

I would suggest to start with CCIE R&S. This will provide you a rock-solid foundation for any of your future endeavors. After the R&S I think you need to study the market and see where the Cisco products are being used mostly. It doesn't make sense to do CCIE in Data Storage when Cisco has only a niche market share. I would suggest think about doing Wireless (WiFi is the future, period.) If you want fancy stuff, and plan to move into consumer market, then go for Voice or Security. Either way, go for R&S first, and then for any other track. Plus, Double-CCIE sounds manly and macho ;)