Short answer: the “best” SEO service depends on your business size, industry and goals — but top choices in 2025 combine a reputable agency (for strategy + execution) with one or two best‑in‑class SEO tools (for research, audits and reporting). Below is a practical, ready‑to‑use guide: recommended agencies by use case, the leading tools, realistic costs & timelines, what to require in proposals, and red flags to avoid. Sources for the key claims are cited after each section.

1. Recommended agencies / service types (by business need)

• Small/local businesses (focus: Google Business Profile, local citations, on‑page): Thrive Internet Marketing, Straight North, HigherVisibility. (clutch.co, linkedin.com)
• E‑commerce (focus: site architecture, product SEO, technical fixes): OuterBox, Coalition Technologies, WebFX. (clutch.co, forbes.com)
• Mid‑market / growth B2B and SaaS (focus: content strategy, technical SEO, scalable link‑building): Victorious, Ignite Visibility, Sure Oak. (clutch.co, forbes.com)
• Enterprise / competitive verticals (YMYL, multi‑country): NP Digital, Rankings.io (legal specialty), large full‑service digital agencies with proven case studies. (linkedin.com, clutch.co)

2. Best SEO tools to pair with a service

• All‑round research + audits: Semrush or Ahrefs (top all‑in‑one SEO platforms).
• Content optimization: SurferSEO, Clearscope, MarketMuse.
• Technical crawling: Screaming Frog.
• Local SEO: BrightLocal (listings, local rank tracking).
• Essentials (free): Google Search Console, Google Analytics.
  These tools are widely recommended in 2025 reviews and buyer guides. (techradar.com, marketingadvice.ai)

3. Typical budgets & timelines (realistic expectations)

• Pricing (typical ranges): small/local packages often start ~$1,000+/month; comprehensive mid‑market retainers commonly $2,000–$5,000+/month; enterprise/agency engagements often $5,000+/month or project retainers much higher. (Individual agency starting prices vary — e.g., some agencies list $1,000–$2,500+ starting plans). (forbes.com, clutch.co)
• Timeline: expect early movement in 3–6 months, measurable/significant business impact often 6–12+ months; some competitive keywords/domains take a year or more. SEO is a long‑term, compounding channel, not an instant fix. (searchengineland.com, ahrefs.com)

4. What to require in proposals / contract (practical checklist)

• A baseline technical audit (sample findings + prioritized fixes). Ask that this be delivered before or at project start. (developers.google.com)
• Clear deliverables and work plan (monthly tasks: content pieces, links, technical fixes) and a 90‑day roadmap.
• KPIs and reporting cadence: rank targets (as a directional metric), organic traffic, leads or transactions attributed to organic search, and specific conversion goals; monthly reports + quarterly business reviews.
• Ownership: you keep admin access to GA, GSC, hosting, domain registrar, and Google Business Profile.
• Proof points: case studies, references you can call, relevant outcomes (traffic, leads, revenue). (clutch.co, searchenginejournal.com)

5. Red flags to avoid

• Any promise of “guaranteed #1 rankings” or guaranteed traffic — results can’t be promised.
• Vague deliverables (“we’ll do SEO”) with no audit, no measurable KPIs, or no list of specific tasks.
• Offshore link‑farms, private blog networks, buying low‑quality links, or tactics that violate Google guidelines.
• Agency insists on owning accounts (GSC, GA, GMB) or long non‑cancelable lock‑in contracts without performance clauses.
  Google and experienced industry sources flag these as warning signs. (searchenginejournal.com, developers.google.com)

6. Quick hiring rubric (scorecard you can use)

• Business fit (industry + past results): 25%
• Transparency & process (audit + roadmap): 25%
• Reporting & KPIs (measurement & attribution): 20%
• Team & communication (who works on your account): 15%
• Price & contract flexibility: 15%
  Ask agencies to score themselves or give references that back up these claims. (clutch.co, searchenginejournal.com)

7. Fast next steps every business should do (even before hiring)

• Run Google Search Console and a site crawl (Screaming Frog) to identify immediate technical issues.
• Install/confirm GA4 and GSC if not already set up.
• Create a one‑page goals brief (primary KPIs, target markets, top 10 competitor sites) to share with agencies for faster proposals.
  These items give you leverage and help weed out poor providers. (techradar.com, developers.google.com)

If you want, I can convert this into a one‑page RFP template (with questions to send to 3 agencies) or produce a 30/90/180‑day KPI plan matched to a small, mid, or enterprise budget—tell me which format you prefer and I’ll generate it.