Intelligent weapons are fun. They don't always have to be extremely powerful, but can give you the opportunity to play an NPC without having to keep track of anything.
There are so many uncreated magical items in D&D that your options are almost limitless... You could hand out a ring that gave its wearer Vampiric Touch at 10th level as a standard action once per day, a scabbard which always made drawing its stored weapon a free action, Bracers of Tickling (Tasha's Hideous Laughter as a touch attack 3x/day), a Bracelet of Teleport Without Error once/week with a 10% chance of changing its wearer into another humanoid race or gender in the process, a Helm of Alertness (as the feat)...
None of these items would be too powerful, and as a player, unique items such as these are much more meaningful than those I've bought or commissioned. In fact, I find the idea of buying or commissioning items on a large scale kind of ridiculous. Of all the high-level spellcasters around, how many of them are actually going to sit around spending XP to outfit any old person who can scrounge up some dough? Not many, I'd wager. What percentage of Wizards are actually going to even have the ability to create any items other than scrolls? Plenty of them would rather be taking metamagic feats, I would guess. Sure, there are Magic Item shops, but only very few, and what they have in my campaigns is far more limited. Just because there's a 16th-level wizard in the city doesn't mean he's going to want to spend 2 weeks making you a Belt of Giant Strength...