可靠 (kěkào) is the most general word for 'reliable' — it describes a person, news, or product you can trust. 保险 (bǎo xiǎn) as an adjective emphasizes safety and being free from risk, while 踏实 (tā shi) focuses on steadiness and thoroughness in work or character. 稳妥 (wěn tuǒ) and 过硬 (guò yìng) are more formal and specific to plans or skills.