I am 42yo. What should my first cycle be?
 

I am 42, 6'2", 210 lbs, very healthy, go to the gym five days a week doing cardio and free weights. I have always struggled to lose weight and this is the lowest I have been in the last ten years. However, I would definitely like to be leaner and more cut.

What is the best cycle/stack for me?

Since this is your first cycle I would recommend test e or test c for 12 weeks at 500mg per week. You could add some dbol or tbol for the first 5 weeks till the test kicks in. Also start hcg 250-300 twice a week starting week 3.

Advice above is good but if you want to go for safe cycle than primobolan and anavar is for you, plus you can add some t3 for increased fat loss. however that depends on your goals.