I dont think there is one controller that can be crowned best because they all have good points and bad points. The most Expensive units are ELOS then you have IKS and Aquatronica followed by Neptune and Light house. All of them work as advertised.
Elos is premo stuff, it is stylish well thought out and includes just about every option you can think of. The only problem is that they are not able to supply USA 110 Volt powerstrips yet, they should have them soon, so you may want to watch this product before purchasing. Also ELOS prices are more than double that of any other controller.
Aquatronica is a new controller and they are releasing a ton of new addons for there unit right now. The Aquatronica is also the most expandable of all controllers and also features easy internet based software updates. Only word of caution is that there is an issue with the salinity probe that will hopefully be rectified soon.
Neptune is releasing some new stuff also but I have no idea when. They are one of the oldest makers and there equipment has been running a long time and is fully proven. The Neptune systems also offer the most open ended software, so if you write software you may find it to be a very attractive unit. The only downside is they have had powerstrip issues and the X10 power feature is very unreliable.
IKS is rock solid and expensive, it is a no frills unit that just works, the downside is that it is not very expandable and has no bells or whistles (dull) Also it is expensive