Just returned from a fabulous time in Barcelona, can't believe how much we fit in in such a short time! Hope this review is of some use :D
The Aerobus only costs around 7 euro each for a return. This can be bought on the bus but make sure you have this in coins! Also, the machine at the bus stop only took notes up to 10 euros! Warning for Easyjet customers - departures have been moved to Zone C which is a good 20-25 minute walking distance from your departure gate!!
Stayed in the Hotel del Comte in L'eixample region. Very quiet here, although a bit of a trek taking 15 minutes to get to Placa de Catalunya. However if you don't mind a walk, this can be quite pleasant, and there is also a number of metro stations (Gruell, Universitat) on the way.
After reading many pickpocket reports we were on our guard and to be honest didn't experience any trouble, see anyone else having trouble or feel unsafe in our 4 days here. I felt quite comfortable walking around with my SLR in full view, and my map out :)
This may have been down to me having my hand in my wallet pocket and my girlfriend having her handbag under her arm. I think sometimes people fall into the trap of thinking that as they are on holiday, everything is safe, everyone is there to serve them and that they will always have sunny weather... this of course isn't awlays the case anywhere you go in the world!
So, general tips apply: Stay away from large crowds (especially on La Ramblas watching the street performers), be extra careful on the metro at busy periods. Also try and keep your wallets etc out of site when not being used.
We were fortunate that we chose this week as it seems from next the temperatures start to drop. We had clear blue sunny skies for 4 days and touched on 20c! In the morning and evenings it was chillier and we needed a jacket, but much nicer than the sleet and rain of the UK!
If you are staying in Barcelona for only 1-2 days then I would recommend the Barcelona Bus, as it travels along all the main sites. However if you have longer and a chance to get your bearings Barcelona is easy to do on foot/bus/metro. I highly recommend getting a T10 card - this gives you 10 journeys and makes traversing the metro stations and getting on the bus so much simpler. When 10 journeys have been finished, this is stamped on your card. Can't remember the exact price but came to about 7-8 euros, so well worth it.
If you don't mind walking, then you can easily walk around the centre of barcelona - 15 minutes from La Padrera to Placa de Catalunya, and then another 15 minutes to the bottom of La Ramblas. From here about the same to Barceloneta, and you can spend hours walking through the many winding streets of the Barri Gotic!
Do make sure you see:
* Sagarda Familia - do get here at 9am so you can be the first in the queue to get the lift to the top of the church for incredible views. The lift only takes 6 people at a time and it can get crowded at the top! If you don't mind steep stairs, take the spiral staircase down - there are a number areas on the way down to step out into the fresh air and see a different part of the chuch.
* La Padrera or Battlo and Passeig de Gracia - Again try and get here early to beat the queues. We went up La Padrera and I can say i have nevber taken so many pictures of chimneys! There is also the view down diagonal to the Sagrada Familia.
* La Rambla - very touristy but the street artists were fun - look out for the outdoor mercat de la boqueria. Look past all of this and you will see some stunning architecture, leading down to the columbus statue and Port Vell.
* Barcelonetta - nice boat, port, harbour area with very good sea food - ignore the new building swith the picture menus and head over the road for more traditional and reasonably priced food (I had the biggest mussels i have ever seen!)
*Barri Gottic - get lost in the winding alleys, full of cafe's restaurants and specialist shops.
* Parc Guell - a highlight of our tour, really beautiful here on a hot sunny day. (recommend taking bus 24 from Placa de Catalunya which drops you off at the top of the park. This leaves you a nice downhill walk to the entrance, where you can then walk to the bus or metro stop (it is a steep climb if you go the otherway!)
* Parc de la Ciutadella - a nice park to relax in after a hard days walking, and can also see down the the arc de triomf.
*** Montserrat - No doubt the highlight of our trip! A 1 hour train journey from Espanya train station, then a jaw dropping cable car ride up to the monstary of montserrat. A further funicular to the very top gives some breathtaking views of the area, a real adventure! If you can make it to the basilica for 1pm where there is a daily choir service, afterwards you can climb up the side to see the black madonna, the holy relic on which this site was founded. Look out for information desks around placa de catalunya or buy your tickets at the station - around 20 euros each for an unforgetable day.
Do make sure you visit some of the local cafes and patisseries for iberian ham bocadillo's, and of course the cream cakes and sweets. If you like hot chocolate you will love the churros and the thickest hot chocolate i have ever had!
At night we ate in cheap-mid range restaurants with the meal coming to around 50 euros for 2 courses and a bottle of wine (although of course there are cheaper/more expensive options on the menu). All were in the Barri Gotic and were quite busy still at 10pm.
First was the Real Circula Artisico, near the cathedral. This is based on a terrace overhead, and has a number of heaters which made eating oustide very pleasant even on a november evening.
Second (and my favourite) was the 4 cats (or 4 gats) restaurant, down a side alley again near the cathedral (don't be fooled by the small looking bar area, it leads to a much bigger room at the back. This has been running for the best part of a century and supposedly Picasso himself dined here. We loved eating upstairs looking over the rest of the restaurant, with live piano adding to the ambiance.
Finally we ate at the El Gran Cafe on d'avinyo, another long running restaurant with a delightful parisian feel.
Any questions send me a pm :)