I think for me it'd be pastel/cream/kawaii items.
I don't actually own everything cream and kawaii and stuff, but when I see it, I stare at for a long time. then take a longer time convincing myself it is not worth spending 20mil on it.
I really like pink things and anything with good hair is a total MUST have for me. I also have a big weakness for things that match whatever I'm wearing.
But for the most part, I try to be smart with what I buy so that I don't waste my gold. emotion_sweatdrop
If an item has armor, especially elegant armor, I have to own it. I also have a thing for swords, but it has to be the right shape, style and colour to tempt me. I love fantasy clothing in cream, white, gold or silver. White, spiky wigs are another weakness of mine.
But most of all, if there's anything that even slightly relates to demonic sort of mistress style... It must be mine. I have a Cat Burglaress I ached for... that I rarely wear now because it tends to dominate an avatar, oh irony!
wigs and hair mods.
oh god if one comes out that i like, i make like, 500 tekteks with it and then try and save up for it.
unfortunately i'm pretty poor most of the time, so lots of pretty hair items remain beyond my reach. sob.
also things that are cute- pink things, frilly things... all the girly items. i'm actually trying to collect sweet lace stuff at the moment. pretty, lacy, pastel and frilly items are my favourites.
i've also realised i have quite a few antlers in my inventory. hm. (my mom actually has real antlers for her altar, which is weird.)
at the moment my main want is an ela the jackalope because that hair is just perfect. emotion_kirakira
/scrimps and saves
Anything rose or moon/lunar theme, I will probably need to add to my inventory at some point. Witch/wizard/mage and other magical items are definite must have items, especially if the item includes a hat.
EIs/REIs are items that I will have eventually. Not exactly a "must have right now" unless I really like it. But whenever I've got some gold, I'll start looking at which ones I don't have yet.