I don't really know whether to recommend RFB or TMO, since there are things I like in both mods...
TMO is supposed to be more "cinematic" and RFB more "realistic". I use both on a regular basis depending on how I feel. RFB has some really nice features, although it also has some annoying ones. Your playing style will be very different using one or the other. I suppose you'll only know which one to use after you try them both extensively.
RSRDC is, quite simply, a necessity. It's a brilliant mod and there are no reasons not to use it.
RoW Pacific Environments is also a must have, as it does great things for immersion and overall graphic quality.
After those three (either TMO / RSRD / ROW or RFB / RSRD / ROW) I go for purely atmospheric mods, such as gramophone music and radio mods (I specially recommend CaptainMidnight's CBS mod, which I link here, as it is not on the first page of the mods section anymore)
http://www.subsim.com/radioroom/showthread.php?t=108756
Those are my must-haves. You will find that TMO / RFB, RSRD and ROW are essentially staple mods in this forum and most people use a combination of the three.