I have always been eclectic, but appropriate. I don't just drop things at random or for cheap effect, but look for meaningful transitions from similar things, & for unique contrasts. Sometimes I can spend long hours working up a very precise set, other times I just wing it. Sometimes a little of both.
Naturally this is all within the context of the situation (early, late, big crowd, small gathering, what music is playing before & after me, etc.). I like all time slots: opening sets where I can play unexpected songs & build up the energy, mid sets where I can seriously rock things out, & chill room & after hours party sets where I can just stretch out & explore. All in all, I just enjoy sharing the music that I love. And I have a wide range to choose from.
This is probably because I began DJing by playing vintage Reggae, & I spent a lot of time dancing in Goth clubs. Neither of these stylees play the exact same tempo & rhythm structures all night long, & songs are emphasized over 'tracks'. OK, reggae can be quite similar in it's rhythm requirements, but I'm playing Reggae from the late 60's to the early 80's, plus Rocksteady, Dub, & a bit o' Ska. That's around 20 years of musical variation! So, once again, eclectic within a set of guiding parameters.
Personally, I can get bored with the sameness of just hearing one style of music, even if I might like that music in small doses; & get really bored with full nights of the exact same music where you couldn't tell one DJ from another if your life depended on it! But I do know that for many people this is exactly what they want, so groovy: to each their own.
Ultimately I think it is worth taking risks to achieve unique effects. I like the freedom.