finally, last but not least, in conclusion

I suppose you remember that when we were learning English in the school we follow the following form of introducing paragraphs

To start with ...
of
Firstly ...
Secondly, Thirdly, etc
In addition ...
Also ...
Furthermore / Moreover ...
Nevertheless / However / Despite of / In spite of ...
On the other hand ...
Regarding / Considering ...


and for conclusion:
1. Finally,
2. In conclusion ...
3. Last but not least ...

My problem to be honest is just with the conclusion. I think I know the other

, наконец,
, в заключение,
, подводя итоги, (summing up, in conclusion)
last but not least - последнее, но не менее важное, чем всё предыдущее - loose translation of the idea.

Russian conclusion and parenthetical structures may sometimes be rather complicated and convoluted.

To start with ... - Для начала...
Firstly ... Secondly, Thirdly, etc Во-первых..., во вторых... , в-третьих
In addition ... - Кроме того...
Also ... - Также..
Furthermore / Moreover ... - Более того; Сверх того; Кроме тот
Nevertheless / However / Despite of / In spite of ... - Тем не менее/ Однако / Несмотря на
On the other hand ... - С другой стороны...
Regarding / Considering ... - Учитывая... / Принимая во внимание..

last but not least - последний по порядку, но не по значению

Еще можно закончить:
Учитывая вышеизложенное (вышесказанное),....