I'm looking at flying Melbourne-Barcelona return next year.

I'm looking at flying Melbourne-Barcelona return next year. One stop airlines include Qatar, Singapore Airlines or QF/Emirates. I'll be flying economy and I'm interested in reading which airline others would choose for this journey. Thanks in advance.

Are you affilliated with any FF program?

I'm a member of both Qantas and Virgin Australia.

Do you hold status or wish to earn points with either?

Qatar has the best schedule (and is oneworld), with swift connections each way, night departure ex-MEL and afternoon departure ex-BCN, running daily. Outbound QR 905 connect QF 139; return QR 140 connect QR 904.

Singapore Airlines is my pick for quality (or a Velocity or Star Alliance FF membership), but the BCN flight only runs thrice-weekly (SQ 68, Mon-Thu-Sat outbound, SQ 67 Sun-Tue-Fri). The connections are quite good. Outbound SQ 228 connect SQ 68; return SQ 67 connect SQ 207. (You can even use SQ 208 if you're a risk-taker, as a 50-minute connection is legal in SIN on SQ.)

I wouldn't use QF/EK transiting in DXB unless you're trying to rack up codeshare legs on QFF or are a Skywards member, as the connections are quite poor (unless you actually want to overnight in DXB on the way back).

The connections on QF/EK are actually pretty good for MEL-BCN. If you are prepared to to QF8407 from MEL, your wait time in DXB is only 2 hours 50 to connect to QF8185 to BCN

Not the other way around. EK186 ex-BCN arrives back in DXB at 0050 and neither the QF- not EK-metal nonstops to MEL leave for over nine hours; ditto for the via SIN flight.

There is the option of the via KUL flight, but that arrives in MEL at some ungodly hour (like 0105). There is the option of a very short (~85 min) connection to EK414, arriving in SYD at 2205, but that also requires an overnight stop.

The earnings rate on Qatar flights is pretty abysmal though, right? If you're looking for QF/VA frequent flyer value then QR should be avoided

Yes, but if the OP is with AA or BA, then QR is the oneworld option.

I would choose SQ

Thank you everyone for your replies, much appreciated. I'm leaning towards SQ or QR.

Is SQ one-stop from AU?

I believe on SQ it's SIN/MXP/BCN. 

SQ does SIN-MXP-BCN 2x weekly and SIN-BCN 3x weekly.

Nein, it's on SQ 68 which is the SIN-BCN-GRU flight.

Ah ok. Thanks for the update.