Gemini is the obvious choice if your work already lives in Google Workspace. The ability to reference Drive files, draft into Docs, and pull from Gmail threads without copying anything around is a real productivity gain. The free tier gives 100 monthly AI credits and access to Gemini 2.5 Flash, which is enough to evaluate whether you want more.
The paid plans are solid but the naming has been a mess: Plus, Pro, Ultra keep shifting price and feature sets. Pro at $19.99/mo is the practical option for individuals who need the 1M context window and deeper research runs. Ultra at $99.99/mo makes sense mainly if you need Veo video generation or you're genuinely hitting Pro limits daily.