Funny thing, for the longest time I’ve been rooting for the (X)Emacs team. It has ESS, AUCTeX, MULE and the whole kitchen sink. But this morning I started to understand the way of the Vi(m).
For you non-computer geek people out there, Vi(m) is like In-N-Out in that it does one thing and does it well. It is low-fat, command line oriented and pretty much installed on all Linux/Unix systems and thus is currently winning my philosophical favor. (X)Emacs is like Walmart in that it offers everything.
The main languages I’ll need it for are R and LaTeX but will occasionally need it to write in bash, SAS, C++, etc.
Any helpful unbiased recommendations? Check out the wikipedia article for more details.