If you like Swype, I would first recommend that you just buy the full version. If for whatever reason you do not want to or perhaps unable to purchase the full version, I would recommend the Google Keyboard. It has gesture typing just like Swype. For the time that I used it, the gesture typing is almost as good as Swype. Swype is just a little bit better, but Google is a good free alternative.
Other keyboards that allow gesture typing that I have used are Kii Keyboard and SwiftKey Flow. Both of these keyboards has a full version that you must purchase.
I am currently using Kii because it has a landscape layout that I like more so than that of any other keyboard I have used. The gesture typing is not quite as good as Swype. I would rate the gesture typing of Kii better than SwiftKey and not as good as the Google Keyboard.
SwiftKey Flow also allows gesture typing. I personally don't like it because after you gesture type a word, the suggestion line suggests the next word. Sometimes it gets the word I type wrong and I want to pick a different word from the suggestion bar for the current word not the next word.