Short comparison — which is better depends on what you want. Key differences and what each brand is best at:

1. Brand character / heritage

• Omega: Broad mainstream prestige, iconic with space and dive-history credentials (Speedmaster Moon watch; Seamaster association with James Bond). Image mixes sport/tool watches and dress pieces.
• Breitling: Aviation and instrument heritage — strong pilot/chronograph identity (Navitimer, Chronomat). More tool-watch, cockpit-instrument styling and bold aesthetics.

2. Design & style

• Omega: Generally more restrained, versatile designs that wear well dressy or sporty. Popular models: Speedmaster (chronograph), Seamaster (divers), Constellation (dress).
• Breitling: Bolder, larger, more technical dials (slide rules, wide bezels). Popular models: Navitimer (pilot chronograph), Superocean (diver), Chronomat/Avenger.

3. Movements & accuracy

• Omega: Heavy investment in in-house calibers (Co‑Axial escapement, many “Master Chronometer” movements with anti‑magnetic tech). Known for robust, well-regarded mechanical movements.
• Breitling: Also develops in-house movements (e.g., B01 chronograph). Offers both mechanical and high‑accuracy quartz (including historically their SuperQuartz). Many pieces are COSC-certified. Both brands make quality movements; Omega focuses on anti‑magnetism and wide third‑party certification programs.

4. Build quality & materials

• Both use premium materials (stainless steel, titanium, ceramic bezels, precious metals). Finishing and case robustness are comparable at similar price points; specifics depend on the model.

5. Price & value

• Overlap in pricing, but typical ranges differ by model and materials. Entry-level new pieces from both start in the lower thousands; iconic or complicated models push to mid‑ and high‑five-figures. Resale/value retention varies: certain Omegas (Speedmaster, certain Seamaster references, limited editions) and some Breitlings (classic Navitimers, in-demand Chronomats) hold value well. Market dynamics fluctuate, so check current secondary-market prices before buying.

6. Service & ownership costs

• Both have authorized service networks worldwide. Service intervals and costs depend on movement complexity; parts/service prices can be substantial for in-warranty and out-of-warranty repairs. Both brands have extended warranty programs in recent years, but you should confirm current warranty length when buying.

7. Wearability & sizing

• Breitlings traditionally run larger and chunkier (though they’ve downsized many lines recently). Omega tends toward a wider range of sizes and often slightly more conservative case proportions. Try both on — comfort matters more than specs.

8. Personality fit / who should choose which

• Choose Omega if you want: iconic, versatile sport/dress pieces; strong technical innovations (anti‑magnetism, Master Chronometer); ties to space/diving history; a slightly more subdued look.
• Choose Breitling if you want: aviation/pilot styling and bold, instrument-like dials; standout chronographs; rugged tool-watch presence and options for high-accuracy quartz.

9. Example picks

• Omega Speedmaster Professional (Moonwatch) — classic manual-wind chronograph and cultural icon.
• Omega Seamaster Diver 300M — versatile, modern dive watch.
• Breitling Navitimer (classic) — pilot’s chronograph with slide rule and vintage appeal.
• Breitling Superocean or Avenger — beefy divers/field-style tool watches.

Bottom line: Neither is objectively “better” — both are respected Swiss maisons with quality builds and in-house technology. Decide by style (subtle vs bold), the specific model you love, movement preference (mechanical innovations vs certain quartz options), and how the watch fits on your wrist. If you’d like, tell me a budget and whether you prefer sporty vs dressy vs pilot/chronograph and I’ll recommend 3 specific models from each brand.