It really depends on what you're looking for and the situation.
Personally, when I'm doing street/bar magic, I like to pack light. The stuff I usually have on me if I know I'm going to do magic is my wallet (and the stuff in it), ring, phone, a deck of cards, some rubber bands, and some coins. Sometimes I'll add a thumb tip, sharpie, or spongeballs. All of these can be used to do various tricks and are either things I would already have on me, or things that don't take up much pocket space.
Obviously this isn't an issue if you have a bag or backpack, which is perfectly fine. Just make sure you know where everything you need is and there isn't dead time of you rummaging through your backpack for the gimmick you need. That's generally why I like to keep everything in my pockets.
I also can't guarantee that I'll have a table so I usually want tricks that can be done almost entirely in my hands or theirs.
I also usually look for tricks that require little to no extra gimmicks. So either tricks I can do with the stuff I mentioned above or objects I can borrow or find wherever I am. Plus, people seem to love it when you can do magic with stuff they know for a fact isn't tricky in any way.
Gregory Wilson's On The Spot 1 & 2 are great resources for impromptu magic that can be done with everyday and borrowed objects.
If it does require extra gimmicks, it either has to fit well in my pockets or take up no extra space whatsoever. This would be things like gaff cards as you can just stick them in the box.
If it's a larger gimmick, I'll only carry it if I feel like the effect is worth it. So this would be things like the omni deck or invisible deck as they hit hard. Plus, the invisible deck is a great out.
As far as openers go, I'd say stick to stuff you're good at and that hits fairly hard. Even if you're advanced, you might wanna do something with little to no sleight of hand to mess up.
I personally tend to start with a simple right card/wrong card trick (the wrong card turns into their selection), slop triumph, or the Chicago Opener if I have the card necessary. Even as someone who's been doing magic for around a decade, I still get shaky when showing new people stuff so I generally stick to stuff I know I won't mess up until I'm a little more comfortable with the audience.
I'd also suggest mixing things up. There's sort of this joke in magic that spectators won't remember most card tricks and will be like "yeah he unlocked my phone, he made a bunch of fake bunnies appear in my hand, he made two metal rings link to each other, he did a card trick". Thus, I always suggest having a bit of variety in your tricks if you're going to be showing them a lot of stuff.
For other tricks, some of my personal favorites for a street setting are:
- Double Cross
- Stairway
- Missing Link.
- The Biddle Trick
- Las Vegas Leaper
- TNR Transpo
- Various tricks with a pen and coin that I've also picked up and strung together into a short routine
- Wikitest
- Code Breaker
- TOXIC
- iCurveball
- Divorce
- Ring Thing
- On/Off
- Double Exposure
- Card to Pocket
- Angle Z
- Hoy Book Test
