I like Lonley Planet Guides. We often use a specialist travel agent because we put together bespoke holidays, eg China, Peru, India, Japan,Brazil, Ecuador, with their expert help. Not a cheap option, but we have had some memorable holidays and experiences. We usually get the flights via Avios and then get the specialist company to suggest an itinerary and I adjust it after reading up on everything. Sometimes I change the hotels too. For example, in our forthcoming trip to China, I am using a fairly new hotel in Beijing they have not used before. I feed back info to them regarding whether they should recommend it or not in the future. We have done this a couple of times before and hotels I have found are now in their brochure!
If it is the USA, I do my own bookings for the hotels and B and Bs. Sometimes, for cities, we just book flight and hotel via BA. This works well and usually the price is very good for high quality hotels. I check out reviews on bookings.com and trip advisor, but the former is the most reliable in my view. Less of the "Chuck is the best bellhop ever" rubbish!
I think if you want a straighforward two weeks in the Med, then there are lots of different avenues to find the best combination of flight and hotel. We do not like really early or very late flights, so prefer a scheduled airline because their flight times are better for us. Yes, you pay more for that and the convenience of Heathrow.
mummymeister - why no holidays in the next few years? You will get withdrawal symptoms!