They're all OK. I’d suggest trying that one. Saying "I would suggest" is conditional upon something. Since there's no condition, it would be grammatically better to say "I suggest trying that one." Sometimes people use the "would" to make the suggestion gentler and less peremptory. In that case, the implied sentence is, "If you asked me, I'd suggest..." I recommend trying that one. This is fine I’d try that one. Here the implied sentence is, "If I were going to a restaurant, I'd try that one."