We have done some great cruises with P&O from Southampton. They also do fly cruises with flights and transfers included in the price if you want to go further afield. We cruised to Norway last year and are going to France and Spain this summer.
I used to think cruises were for old people and were a bit fussy until my friend went on one and raved about it. The things we liked are:
No flights and going straight from Southampton so park the car, get on the ship and the holiday has started.
Very similar price or cheaper than going to a bog standard all inclusive and you get to see a variety of places.
Plenty of dining options included on the ship including more formal restaurants, poolside pizza, buffet, fish and chips takeaway etc so lots of variety and something for everyone.
Excellent kids club and P&O work to UK childcare ratios etc. DDs absolutely loved going to the kids club and therefore DH and I got time to chill out in the hot tubs or go to a bar together etc.
Not at all stuffy. If you want to dress up that's fine but if you don't that's fine too.
The quality of the shows and entertainment is usually really good.
Overall we find it a very relaxing type of holiday.