Is there a phrase "I'd just go with"...
...to say "I'd choose"
Or what are alternative ways to say that?

Question

Is there a phrase "I'd just go with"...
...to say "I'd choose" 
Or what are alternative ways to say that?

Answer

Here is an example
Waiter: What would you like to order from the menu?
You: I'll just go with a coffee thanks

Answer

Yes there is. 'To go with' is a phrasal verb meaning to select or choose. It's not classified as informal English but it tends to be used in a more informal context. You can also use select, opt for, decide on, pick out and take.