We stayed here, the Hotel Phoenicia, 8-11 May 2008. It is a good hotel with friendly and helpful staff and with a good bar and restaurant.
Two things to note which may or may not affect you: the first is that my room had a connecting door to the next room (114 to 112 should it matter). My first night when my neighbour came back from, obviously, a very good night out, I could hear everything that he did: from the sighs of oh dear to the bumping into furniture. He was not being loud at all he tuned the telly on quite low but I could still hear everything. I am sure he would have heard me too as I walked around. Speaking to my companions the next day, it looked like this was just my luck to have a room with a connecting door and so with no noise insulation between the rooms but it could be a common thing with an older hotel like Phoenicia so bear it in mind when booking in.
The second thing which again may be just my room was the noisy air conditioning. I had turned it off because it was too distracting when trying to get to sleep but in the end it came to my rescue as it covered over the noise of the telly from next door (he fell asleep with it still on it was still on the next morning).
So, it worked out I had a very enjoyable stay after that first night. But it could have easily gone the other way no sleep or air conditioning for three nights!
The only meal we had in the hotel was breakfast which is buffet style and self service. Selections of hot food (sausages, eggs, bacon, waffles, baked beans, grilled tomatoes etc) and cold (cereal, yoghurts, cold meats, dried fruits etc) and a toasting grill. The breakfast staff will come round and provide coffee or tea and juices. This was all very fine.
The bar is small but very well stocked with beers, wines and especially spirits including some local varieties which I would suggest you try! Staff here are friendly without being intrusive.

The hotel does host weddings and other big events (there was one while we were there) but besides the occasional rowdy guest these do not get in the way. Only word of advice is if you want to try the brasserie then book ahead but again, they were fully booked the night we tried, but offered to fit us in nonetheless if we could be very early (i.e. right at opening time at 6.30). As it happened that didn't suit us but it shows that the hotel does have its heart in the right place and from the front desk to the concierge to the bar and restaurant staff.
A word of warning about Valletta, a city which I have fallen in love with, so take this as you will. It is a fascinating and intricate place despite being on a grid system.
We had three guide books (Lonely Planet, Rough Guide and the AA Essential Guide). As with any guide book there is always a chance that things will be out of date. It wasn't that exactly but a recurring theme in our 3-and-a-bit days in Valletta was Oh, it's closed. For restaurants that wasn't so much of a problem because there was usually something around a few corners away (but be prepared to walk a bit) but for museums it was more of an issue. Both the War Museum (next to Fort St Elmo) and the War Rooms (in the bastion) were permanently closed as of May 2008. No indication of this before the holiday, and no sign at either place when (if) they would open again. The WWII museum (Malta at War) in Vittoriosa (yet more catacombs and a 1943 propaganda film with Laurence Olivier narrating) was open.
For restaurants it was annoying that recommended places were closed but either Valletta is well catered for, or we were lucky in the places we ended up, having found our intended place was not open. But book ahead! After the first night experiences we went to a place the night before and booked then. It worked out very well. Places we went and that I would recommend are:

Capistrano a newly renovated place, very small but with great food and wine. We walked in without a reservation and got a table for three (about 7.45). Everyone who came in after us without a reservation (and there were about 5 couples or groups who tried) were turned away.

Malata Republic Square I think anyway opposite the Grand Masters Palace. Very busy and alive with excellent caricatures of, we presumed, Maltese politicians and celebrities. Food superb and service great. But this is a general rule be prepared to sit back and wait every now and again. They have live music occasionally.
Gianninis definitely have to book here as this was one of the Guide Books recommendations which is still here. You get a lovely welcome and a drink downstairs before heading to the third floor restaurant. The night we were there it was a Force 9 gale (I kid you not while London was enjoying 27!) so the view out of the billowing windows had an extra frisson. Up market food and very attentive service (they took our wine and water bottles away to a nearby table but always ensured our glasses were not empty).
Leglinin tapas bar. Now if you can go here! Leglinin is in a basement: five tables (about 18 people) and the kitchen is a two hub gas stove and microwave right in the corner of this small basement room. Sounds awful but I tell you that we had the best food here of all and we had not been disappointed in any of the previous places! The chef and prepares everything as you ask for it and in full view. Amazing what you can do with a two hub gas stove and microwave! The wines are all around you and often he will stretch past you in order to get hold of a bottle. But the tastes he comes up with are brilliant. We had the vegetarian terrine (peppers and mushrooms), the spicy rabbit (truly one of the best dished I can remember) well, I won't bore you with all the dishes! Whats on offer, which is a small selection in comparison with many tapas bars, changes depending on whats available and, no doubt, the chefs mood. But go there if you can: both the food, and the experience of watching Chris cook for his guests many and varied requests, is uplifting. We went on Sunday (everything else being closed, of course) but Leglinin was open so it was by chance we ended up there but it proved to be one of the best.

Generally in Valletta and in Malta we did have to adjust to a different sense of time-keeping. Things aren't open when you expect them to be (including when they say they will be); the place is empty and quiet all too often including at night (but not Saturday morning); and, although our guide books were recent (2007) things have changed more than weve found in other places. But I would say if you are interested in getting to know a place (even over only three days) then you will be amazed, annoyed, engaged and delighted by Valletta and Malta. Three out of four isn't bad, in my experience.