public transport from the airport...???

Bus #36 - get off at KM 27.5 from Changi at the National Museum and the walk to the Ibis is about 650 metres.
Catch MRT to Bugis station and the walk to the Ibis is the same, about 650 metres.
Although the walk from the National Museum is probably easier as it's just a straight walk up Bencoolen Street.

The faster choice is by MRT as the bus service may encounter minor traffic jams as it meanders through the Marine Parade and Katong area before reaching the city area, although you may get to see more of suburban Singapore by bus.

It is also easier to miss a bus-stop than an MRT station.

Exit Bugis Station on the left hand side, get up the escalator, walk back towards the traffic junction, cross the street to the KFC outlet, turn left and walk towards the MacDonald outlet. Turn left, and then turn right (towards the back of the building across from MacD) which is a pedestrain mall. Walk toward the end of the mall until you reach Bencoolen Street (you can see Sim Lim Square across the road) and the Ibis Hotel is right on your left hand side.

As you will be arriving at night, you will not be able to see anything from the bus, so the MRT is the only ideal choice.

For transport to and from the airport try the airport shuttle service. Runs 24 hours a day and takes you to your hotel door. Cost is S$9 one way. See following link for all the options including costs

http://www.changiairport.com/changi/en/airport_guide/tofrom_ap/ap_tocity.html#ass

Many thanks to all of you. I think the best option for me would be to take the shuttle bus, provided it takes me all the way to my hotel.... It's expensive compared to the other options, but I guess it's still much cheaper than a taxi... I can always take the MRT when I'll go back to the airport!

a taxi will be under $20. including your luggage. I went from Changi to Farrer Park for $15

Here: map of MRT, is a map of Singapore's MRT.

It's expensive compared to the other options

Jeez, if you are scrimping over $3, maybe you should rethink your budget.

I've just come back from my travel agent (I'm trying to work out hjow to get to Singapore in early january), and I picked up a brochure about the Ibis.

The brochure says that the Ibis is within walking distance of Bugis MRT, and little India MRT.

If you want MRT, I would reccomend Bugis because that is on the same line as the airport line.

personally though, with luggage and sharing, why not taxi?