We visited Chrishi Beach twice during our Nevis week -- once during the day and once for dinner.
The little tiki bar on the beach is really cute, serving up perfect, refreshing, island-y juices and cocktails. (Note: The beach is a little rocky/coral-y, so you'll have to go down towards the ferry dock to swim.)
The dinner and service were great -- we only wished we had eaten there earlier in the week so that we had time to dine there twice! We had mahi mahi and burgers, plus dessert. Everything was delicious.
The vibe was a little "Euro" which made it funky and hip, a nice night out.