They're really not a must-have for the PC version, in my opinion. I've had Skyrim since it was released, and the only mods I've installed are performance and graphics tweaks, Midas Magic (now, this one basically is a must-have for mages, if you want them to be very powerful), a couple of house mods, and a mod called "Scenic Carriages" which makes carriage rides either instant or you can view the whole ride as if you were really riding them.
I've never installed, nor will I ever install any kind of texture mods, skimpy clothing, body mods, "beauty" mods, anime mods, so forth. I don't like texture mods because I've had problems with them before on previous TES and Fallout games, and the skimpy clothing, body and "beauty" mods, as well as anime mods make me want to cringe, and it irritates the bloody insanity out of me when I see people using them.
If you want to really enhance your game and/or immersion though, the two mods I mentioned, Midas Magic and Scenic Carriages, would really be good choices.
