Similar meaning (summarizing/concluding):
* Finally
* Therefore
* Thus
* Consequently
* In summary
* To summarize
* To conclude
* In brief
* In short
* Ultimately
Similar structure (preposition + noun):
* In essence
* In effect
* In retrospect
* On balance
* By way of conclusion
Words that sound similar:
* Inclusion
* Conclusion (the noun form)
The best alternative will depend on the specific context and what you want to emphasize.