Formal:
* Therefore,
* Thus,
* Consequently,
* To summarize,
* In summary,
* To conclude,
* Finally,
* Ultimately,
* In closing,
Informal:
* So,
* All in all,
* In short,
* To wrap things up,
* The bottom line is,
* The key takeaway is,
More specific:
* Based on the evidence presented,
* As a result of these findings,
* Taking everything into account,
* In light of the above,
Creative:
* To leave you with this thought,
* The message is clear,
* The takeaway is simple,
The best alternative will depend on the specific context of your writing. Consider your audience and the tone you want to convey.