Ryanair - if you have priority boarding and the bag looks carry-on sized you'll get on. They can always ask you to put it in the sizer, and if it's oversized then you'll have to pay to check it.
TAP - they have sizers at the gate - if it doesn't fit, under the plane it goes. YMMV on whether they check. They're more likely to weigh it if you go to the check-in counter.
VY - same.