To travel from Brussels airport to/from Antwerp, best choice is the Airport Express bus. At €10 it's cheaper than train (the Diabolo tax only applies to trains, not the bus).

For other inter-city trips, the train seem the best option.

I wouldn't consider trains expensive in Belgium. Transport by train are quite heavily subsidised by the government. With the already mentioned rail pass you can travel between almost any belgium city for 7,60 Euro's.

Buses are ridiculously cheap (again due to big governmental subsidies), however cars are more subsidised. Quite a large proportion of the population get a tax friendly car from their employer. The result of this is massive congestion around the major cities, but also unreliable bus services. It simply isn't worthwhile to create a frequent intercity bus service, because due to cheap cars, almost nobody relies on buses.

Your best bet between the different cities is to rely on trains. However, it is worthwhile to follow the belgian news outlets in the days before your trip. If there are any strikes eminent, you might want to reconsider your trip. Last year general strikes disrupted the railroads often Now the unions are rumbling again, suggesting new strikes.

I am so confused by everybody advising you to use the train and their answers getting so upvoted. It's definitely by far the most convenient and quickest option, but it's also definitely not the cheapest option as travelling by a combination of local buses can be significantly cheaper.

Brussels and Bruges

Bus: Operator De Lijn, with a day pass it's €5,- (you got to buy this at the booth or from the ticket machine, in the bus it costs €7,-) or €15,- for a 5 day pass (€18,- in bus).

Train: Standard ticket costs €14,10, if you're under 26 you can bring it down to €6,- with a Go Pass 1 (as it doesn't sound like you will be doing enough journeys for a Go Pass 10).

Brussels and Ghent

Bus: Operator De Lijn (example connection*), with a day pass it's €5,- (you got to buy this at the booth or from the ticket machine, in the bus it costs €7,-) or €15,- for a 5 day pass (€18,- in bus). You can also buy a 10 hour pass (Lijnkaart) which costs €14,- and results in this journey costing €2,80.

Train: Standard ticket costs €8,90, if you're under 26 you can bring it down to €6,- with a Go Pass 1.

Bruges and Ghent

Bus: Operator De Lijn (example connection*), with a day pass it's €5,- (you got to buy this at the booth or from the ticket machine, in the bus it costs €7,-) or €15,- for a 5 day pass (€18,- in bus). You can also buy a 10 hour pass (Lijnkaart) which costs €14,- and results in this journey costing €2,80.

Train: Standard ticket costs €6,50, if you're under 26 you can bring it down to €6,- with a Go Pass 1.

P.S.

Do note that De Lijn only operates the northern half of Belgium and only half of Brussels. Brussels airport is operated by De Lijn buses, Charleroi Airport is not. It's also good to note that Google Maps is able to find connections that De Lijn itself doesn't find (and yes, those connections do work).

My advice would be that if you would choose to use day passes then stop on the way a lot as well, because as I said before, it's definitely not the fastest option.

• Depending on factors I do not fully comprehend the link might either give the bus connection for the current time as departure or the intended connection (both connections are about 2 hours). Click the "More options and times" link to find the best fit for your case.

The train is not that expensive in Belgium. It even tends to be cheaper than in, say, France or Germany. For example, Brussels-Ghent is €8.90 one-way for an adult and there are also multiple discount offers that could be relevant.

There are many long-distance buses to or from Belgium but I don't think there are any for trips within the country and I doubt they would be much cheaper. So apart from hitchhiking or possibly ridesharing or piecing together several trips with local buses (timetables can be found under delijn.be, use the little checkbox under “means of transport” to exclude trains), you don't have many options. The only exception might be airport shuttles, especially considering the fact that there is a special surcharge for trains to Brussels Airport.

Belgium might not be Norway but it's still a Western European country with relatively high income and petrol prices, you are not going to find any simple way to travel between cities with public transportation for one or two euros…

There aren't many interbigcity buses. There is one company (http://www.flibco.com/en) which provides cheap and good buses if you come from an airport to some major cities which might be interesting to you.

If you come from Brussels airport, keep in mind that there's a Diabolo tax applied. This results in a cost of 26€ to go from there to Ghent, give or take a few euros when you go to Bruges or Antwerp instead.

Buses by "De Lijn" (Flemish bus/tram agency) typically don't cross province lines. There might be a few that have the borders as their work area but typically most are concentrated around the big cities and those that are, don't go all the way to another one.

Your best bet is the Go Pass which gives you 10 rides for 5€ each if you're under 26. Keep in mind that you need a pen to fill it in (date, origin, destination) and that you fill it in before or right after you get on the train. If you are above 26, consider a Rail Pass for 10 trips, 7.6€ each. You won't use all of them but it will still be a lot cheaper than buying individual tickets. For example a quick look for Brussels-Brugge (return) today (non-weekend) would cost €28.20.

I don't recommend not buying a ticket because although the cost is relatively low for a ticket on the train (7€ or 14€ surcharge, I forgot the exact amount since there was a recent change), your rides will be long enough to very often have a conductor check on you.

If you're going to use the tram: it's always commendable to buy a ticket but I have only seen one checkup in it in Ghent in my entire life. There are ticketing machines outside the tram stops.

If you take the bus, you can ask the driver for a ticket, you can use one of the ticketing machines at the stops (only in cities) or you can buy a ticket with your phone.