Which no-frills passenger airlines are known for transparent baggage fees and online self-service changes?

A few no-frills / ultra-low-cost passenger airlines are especially known for being fairly upfront about add-on fees like baggage, and for pushing most booking changes through online self-service rather than by phone or at the airport:

• Southwest Airlines — famous for relatively transparent policies, including no standard checked-bag fee for the first two bags and easy online changes.
• Spirit Airlines — very no-frills, with baggage fees shown during booking and most changes handled online.
• Frontier Airlines — similar ultra-low-cost model; baggage fees are usually clearly presented, and changes are self-service online.
• Ryanair — strong emphasis on online management, with baggage and change fees disclosed during booking.
• easyJet — low-cost European carrier with fairly clear baggage rules and online booking/change tools.
• Wizz Air — another European ultra-low-cost airline, known for online self-service and explicit ancillary fees.
• Jetstar — low-frills carrier with online check-in and add-on fee structure displayed during booking.
• AirAsia — well known for “do-it-yourself” booking management and clearly separated baggage add-ons.

If you want, I can also give you a “best for transparent fees” shortlist by region (US, Europe, Asia-Pacific).