I have a big weakness for the gallery style frames, with the minimal black metal frames and and a nice mat with probably a slight hint of warmth in it. I like how as a frame, it tends to get out of the way of an image, at least for photographic images, and seems to work equally well for both b&w and colour. For paintings, give me anything, as long as its appropriate to the piece :)
personally i think there is a couple of approaches
1 minimalist simple frame and mount – then can use consistently across lots of images etc
2. some images look waaaaay better when adding proper presentation, so complementary coloured mounts, and frames, design ques etc
ikea stuff is cheap as chips, BUT if your selling images or wanting them to last any length of time, DO NOT put them in ikea frames. the materials are really not the best
if you want some help with stuff give me a shout, i am based in dun laoghaire and can print, mount and frame most things