Mariner of the Seas- This was our very first cruise, we arrived at the port in LA around 1pm, and were onboard within 30 minutes. This was an easy and seamless process.
If you want to start using the pool etc when you get on board then remember to pack a day bag, as you don't get your luggage delivered to your stateroom until later on. We had lunch in the windjammer cafe and this excellent.
Our stateroom was bigger than I thought and the quality on bed linen etc was high. Our stateroom attendent for the week was Pamela, and she could not do enough for you. Each night we came back to bed folded down and an animal made out of towels etc, which was cool. Fresh towels if we had used them since the morning and ice bucket always full with fresh ice.
Cabins, bigger than I thought, plenty of cupboard/storage space. Bed was very comfy, very clean and water pressure in shower was excellent and always hot. Next time I would have an outside cabin with window as having no natural light was bit disorienting as totally pitch black