Short answer: it depends on your style and budget, but for an all‑round, Australia‑focused option THE ICONIC is the best single site (huge men’s selection, fast/free shipping options and 30‑day returns). (theiconic.com.au)

If you want alternatives by category:

• Best all‑round / biggest selection: THE ICONIC. (theiconic.com.au)
• Best for premium/designer department‑store shopping: David Jones (wide designer mix, styling services). (davidjones.com)
• Large department alternative / big range and frequent sales: Myer. (myer.com.au)
• Best for streetwear, youth and curated trends: General Pants Co. (generalpants.com)
• Best for fast, trend-led international and value buys (AU site): ASOS Australia. (asos.com)
• Best for made‑to‑measure/tailoring in Australia: InStitchu (custom suits & fit guarantee). (info.institchu.com)
• Best for high‑end international designer pieces that ship to AU: MR PORTER (international luxury retailer with AU delivery/returns info). (mrporter.com)

If you tell me the style you’re after (e.g., business suits, casual/surf, streetwear, sustainable brands) I can point to the single best store from the list above and give shopping tips — or I can just give more picks for a specific budget.