What's a good substitute for Worcestershire sauce?

Soy sauce. This is my go to when I run out, the flavor works really well, especially with mince and potatoes.

How about Magi?

Why are you avoiding it? If it is to stay away from fish, soy and a little bloop of ketchup might give a similar tangy-salty profile without having to go out and source tamarind. If you don't mind fish, A-1 is a good choice.

A-1. The primary ingredient is Worcestershire.

I was thinking along the same lines as pierino and Sam1148--I'd use fish sauce plus some tamarind. Then I started thinking, that mamilli08 might not be in a group of people who have fish sauce and tamarind but not Worcestershire. And I decided that it depends on the recipe and what's in the cupboard. Leaving it out without substitute could even be an option.

I'd go for soy sauce. A bit of red pepper and vinegar, warm that up in a microwave. Anchovies would be next elements--but if you don't have W sauce you probably don't have anchovey--or your asking because of allergery.

The next elements are sweet...a bit a sugar, a bit tamaraid..So add a tsp of steak sauce like A1. Then a bit of onion and garlic.

Anchovy might work, they can dissolve. There really isn't a sub for it. Fish sauce in some dishes perhaps, what are you making?

I have used soy when I'm out. It's not the same and you don't want to use much. In a burger, you could also just leave it out since there isn't really a substitute.

If you don't mind a bit of Asian flavor, what come to my mind is the oyster sauce. Supermarket or Asian market should have it.