For self-managed super fund (SMSF) investors, building a diversified portfolio of high-quality assets is important for long-term wealth creation.

While individual stocks can be rewarding, exchange-traded funds (ETFs) offer a simple and effective way to gain broad exposure to world-class companies while reducing risk.

If you're looking to buy and hold ASX ETFs for your SMSF, here are arguably three of the best options on the ASX right now.

iShares S&P 500 ETF (ASX: IVV)

One of the best ASX ETFs for long-term growth is the iShares S&P 500 ETF, which provides exposure to 500 of the largest companies in the United States. This includes global giants like Apple (NASDAQ: AAPL), Microsoft (NASDAQ: MSFT), Walmart (NYSE: WMT), and McDonald's (NYSE: MCD), which have historically delivered strong returns over time.

The S&P 500 has consistently been one of the best-performing indices worldwide, averaging an annual return of approximately 10% over the last century. This could make the iShares S&P 500 ETF an excellent choice for SMSF investors looking for steady, long-term capital growth.

Betashares Global Quality Leaders ETF (ASX: QLTY)

If you're looking to invest in some of the highest-quality companies worldwide, then the Betashares Global Quality Leaders ETF could be a fantastic option.

This ASX ETF tracks an index of global companies that score highly on key financial metrics, including high return on equity, low debt, and strong earnings stability. The result is a portfolio of elite businesses with a track record of outperforming the broader market.

Some of the ETF's top holdings include Apple, Visa (NYSE) V), Johnson & Johnson (NYSE: JNJ), and ASML (NASDAQ: ASML), all of which have built durable competitive advantages in their industries.

Because this fund focuses on high-quality businesses, it could provide strong risk-adjusted returns over the long run, making it an excellent SMSF investment. No wonder Betashares' chief economist is tipping it as one to buy.

Betashares Nasdaq 100 ETF (ASX: NDQ)

For investors looking to capitalise on the technology megatrend, the Betashares Nasdaq 100 ETF could be a top option.

This ETF provides exposure to 100 of the largest non-financial companies listed on the Nasdaq stock exchange, including Apple, Microsoft, Alphabet (Google) (NASDAQ: GOOG), Tesla (NASDAQ: TSLA), and Amazon (NASDAQ: AMZN).

Technology has been one of the best-performing sectors over the past few decades, and with AI, cloud computing, and digital transformation accelerating, this trend is unlikely to slow down.

And while tech stocks can be more volatile in the short term, a long-term holding in NDQ could help drive significant growth in your SMSF portfolio.