otherwise, sell, sell, sell ... the only things you really need are alchemical ingredients :peace:
Game Widow must be tired today, because here are a number of other items besides alchemical ingredients that Geralt may want.
You can make a much better steel sword than the one you start with if you collect three meteorites (red, blue, or yellow; any three will do) and take them to a blacksmith. You can also make a much better silver sword if you collect any three asronomical runes (earth, sun, or moon).
You will occasionally find temporary sword enhancements, such as diamond dust, grindstones, whetstones, and non-astronomical runes. Whetstones only increase your damage by 10%, but grindstones increase it by 20% and diamond dust by 40%; if I were you, I'd save every diamond dust I could get my hands on and use them on the relevant sword before boss battles, that or the Perun rune stone or the Svarog rune stone.
You'll occasionally need beer for drinking contests. Most of these are quite optional, but there's an important quest-related one near the end of Chapter 2, so you'll want to save some beer for that. You'll also want strong alcohol (anything that isn't beer or wine) as a base for potions. (Strong alcohol comes in several qualities, but since even the worst quality can be turned into high-quality White Gull, which can be used as a base for any other potion, any strong alcohol will do.)
Also, there a number of items you may want for quests:
Spoiler
There's a quest that starts in Chapter 3 and doesn't finish until Chapter 5 that requires one of most of the kinds of teeth that Geralt will find along the way -- including things that contain teeth, like barghest skulls -- so it's good to keep one of every kind of tooth or jaw in your stash at the inn, especially those kinds of teeth that are encountered once and never again (such as barghest skulls -- they're ubiquitous in Chapter 1 but never seen again after that). This quest is optional but has a very nice reward, so most people like to do it.
There's a quest near the end of Chapter 2 for which you'll need some rose wine, cherry cordial, and Temerian Rye. As a follow-up to this quest, you may want some red roses.
Many quests become easier if you have a certain item, and this sometimes varies with the dialogue line that you happen to trigger. A certain important person might want golden gloves, or she might not. Another person will help you if you trigger the right line and give her red gloves. Yet another person will give you some information if you give her a red shawl when she first mentions it.
There's an optional quest in Chapter 3 that will be cheaper to perform if you have a sapphire handy.
There's an optional quest in Chapter 3 that requires either a silver amber ring or a ring with rubies in it.
There are two optional quests in Chapter 4 for which you'll need food -- five loaves of bread in one case or some meat in the other case.
If you're trying to bed all or most of the women, you'll want some gloves, a diamond, a shawl, some tulips....
(There might be a few others -- this is off of the top of my head.)
And of course, you'll want to read any book or scroll before you sell it.
