Hendricks is different than standard gin. While gin is usually flavored primarily with juniper berries, Hendricks focuses on cucumber.

That said, my go-to gin cocktails are:

• Martini. I like Plymouth Gin for a martini. Plymouth (a brand and a style) is less junipery than the London Dry gins, which is the most common style.
• Negroni. A perfect aperitif - equal parts gin, Campari, and sweet vermouth. You have to like a bitter-sweet dichotomy. Be sure to measure the ingredients to ensure you get it right.
• Gin and tonic. You said you don't like the bitterness of tonic. I like the bitterness of tonic - I don't buy Seagrams/Canada Dry because they are way too sweet. Fever Tree and Q Tonic are good tonic waters for me.
• Gimlet. Gin and Rose's lime juice. Like lime candy. THough I think I like a vodka gimlet better.