Have been to Sri Lanka (which is a beautiful place) and on safari twice but not to Mexico.
Safari every time. There is nothing like it. Every second of the whole experience was amazing! Without trying to sound like a complete year, it was utterly life-affirming and would be my choice any day of the year!
Sri Lanka is a wonderful country too though and a fascinating place to visit.
I have been on safari and to Sri Lanka. Loved both. You can do a bit of animal spotting in Sri Lanka. We also visited Kandy, an ancient ruined city, tea plantation, travelled on the local train to a town in the south on the coast. Plus Colombo.
On safari we went to 3 or 4 different parks so saw a great variety of savannah animals and also at a lake and treetops where the Queen became the Queen.
Make sure you do a couple of safari areas within Kenya and try and think what animals you would like to see because some areas are better then others for specific wildlife. At Christmas the wildebeest have gone back to Tanzania. I would also consider Tanzania for a safari at that time of year.
Nothing beats a safari! The camps are brilliant and it’s exciting. We took DDs when they were young teens and camps such as Explorer and Governors (where Big Cat Diary was based) are very good and some companies do family holidays to Kenya which are excellent. We went with A & K but there are others.
I quite like the idea of Sri Lanka. I haven’t been but there is a cultural and religious element you won’t get in Kenya.
I think Mexico has a lot to offer. Travelling around is much more worthwhile. I would look at Costa Rica too.
I think people are friendly everywhere (some older Russians are a bit sour!) I think food can also be excellent everywhere too. I think the type of holiday you want rather than people or food is the determining factor.
I lived in Sri Lanka for three years. It rained every single Christmas we were there - and had generally been cloudy and a bit miserable from Oct/Nov. Generally perked up a bit driving into work first day of the New Year. Although it was miserable last Jan and I nearly killed my parents by taking them to the Hills and giving them hypothermia.
By all means go to SL. But don't bank on it being hot and sunny for Christmas.
March/April/May tended to be the hottest months on the west coast.