I was lucky enough to play several new courses on my trip through Ireland and Scotland. Any of them standing alone I would consider my best new course I played for the first time this year.
Of course there are the two "best of the best" by default of reputation and historical significance, those being TOC and Portmarnock. I will commit sacrilege and with deference to the "pilgrimage" to the epicenter of golf, and I will lean on Portmarnock for best of the best to my personal taste.
But, for my personal world view of golf, what I like in a golf course including solid golf design and exciting playablity, I'll say the best courses for the first time and hopefully not the last were, Connemara Links in Ireland, and home course of Martin Bonnar, Leven Links. Those two courses have everything I love in golf, with special emphasis on modest home town or area roots that does not rely on the conventional wisdom of the prestige of the most high profile courses sought out by 'belt notchers'. These two courses offer the feeling of a true local golf community with outstanding design to boot.