A few powerful magic items for low level characters

[5eNeedsDarksun]

I'd say my best experience as a player around magic items was in Curse of Strahd. We didn't get many items, but several of those that we did get were well beyond the power of what could normally be expected in Tier 1 and early Tier 2. They tended to be unique and interesting; we never were in a position to want to 'trade up'. Acquiring the items was memorable, and for the most part I didn't think they unbalanced the game particularly. This was I think due to items that tended to scale with character level, some of the items not being optimal for the characters that got them (though 2 were) and the lack of volume of lower powered items.
I'm prepping to DM Descent into Avernus at the moment, and I'd like to adopt much the same approach. My general thoughts are that some items remain relevant for levels 1 through 20, particularly those that provide a flat bonus, whether that be to attacks, saves, turning, or what have you; or ones that scale with character level. Ones that seem to go from overpowered to about right to not really worth it (particularly if they require attunement) are things like wands that duplicate spell effects.
So what kinds of magic items do you think meet the criteria? Things that are unique and powerful, but tend to remain about as effective through many levels?

[PattThe]

I give players as low as Level One the Cittern from the Instruments of the Bardic Colleges item in the DMG. If the party has a bard it's really nice to have them slowly unlock more of the spell powers as they go on their mission to deliver it to an agent for some magical item trading. Healing, Mobility, Defenses, they're great to loan to any character.

[BloodSnake'sCha]

Items like instant fortress are always relevant as a bomb and cover creation.

Ever smoking bottle is useful unless the enemies have true/blind sight or termoseanse.

Stuff that grant flight is always relevant like broom of flying.

Stuff that grant immunity is always relevant like Periapt of Proof against Poison.

Stuff that grant advantage and or disadvantage are always useful.
(Mental of spell resistance, cloak of displacement and more, eye of minute seeing, sentinel shield and more).

I can check with one of my players character sheet in a high magic game.
His sheet is full with items like that.

[PattThe]

Keeghom's ointment. Healing potions are nice, but giving a party disease removal and going "Aside from class features, these doses are all you have for the campaign unless you seek out more. Good luck."

Then throw lesser otyugh's at them.

[borg286]

Here is my list of uncommon magic items I find quite powerful. So much here that I don't find many rare items I want offer the attunement items here.

Cloak of Protection
Eyes of the Eagle
Gauntlets of Ogre Power
Hat of Disguise
Instrument of the Bards, Fochlucan Bandore
Living Gloves
Mizzium Apparatus
Pearl of Power
Weapon of Warning
Stone of Good Luck
Winged Boots
Staff of the Python
bloodwell vial
Rod of the pactkeeper
Shield, +1
Weapon +1
Broom of Flying
Boots of Elvenkind
Gloves of Thievery
Goggles of Night
Sentinel Shield
Wand of Secrets
Pipes of Haunting

[Izodonia]

Luckstone, always. +1 to every skill and saving throw and to initiative? Given the choice, I'll always take the magic item that makes me 5% better at everything.