Originally Posted by
resnullius
i maxed cannons first because they were so cheap and fast. they also help against lvl 6 giants (my bane as a TH8 farmer)
i'm in the process of maxing teslas now, with lvl 5 and 6 teslas (i upgraded two teslas, one air defense at a time). i don't know what base set up you have, but if you use an inner core for dark elixir/gold, a lvl 6 tesla is simply amazing. its limited range (so it doesn't get distracted), fast attack speed, and ability to one-shot lvl 5 wallbreakers simply can't be understated. they're effectively a guarantee that your attacker will have to beat on your walls with troops because wallbreakers won't be able to clear a path. lvl 6 teslas also obliterate lvl 6 giants.
i'm upgrading archer towers last. they are more expensive and slower than cannons, and their ability to target air is off-set by the fact that i have lvl 6 air defenses anyway. their marginal benefits from hit to kill is also underwhelming. finally, as a farmer, i really just don't see very many dragon/heavy air attacks (i'm sure my lvl 6 air defenses help deter would-be attackers, too).