Samson was strong but couldn't rely only on his strengths. His strength needed to be fused with God's strength. The defining aspect of Samson's life was his guidance by the power of the Spirit of the Lord. This phrase appears five times throughout Samson's story, always in reference to God giving him extra strength or guiding his life in some way.
God used Samson to overcome the Philistines. But even while Samson was working within God's plan he was overcome at the same time by his own weaknesses. He appears to have had a weakness for women, twice giving away important information to please his wife and once nearly being captured while he was staying with a prostitute. He also appears to be quick to anger.
But God worked through his imperfections to save Israel. In that sense, Samson is the imperfect savior. He saved the Israelites, despite his own flaws, by God's power. He reminds us that our strongest strength is found in working with God and that God can overcome our own weaknesses so his will can be done. But Samson also reminds us of Jesus, as his imperfection points the way to the perfection found in Jesus.